Let's see if OE syntax can save a piece of wretched prose, namely, the opening of Dan Brown's The Da Vinci Code:

Jacques Saunière, renowned curator, staggered through the museum's Grand Gallery's vaulted archway. He lunged for the nearest painting, a Caravaggio, he see could. Grabbing the gilded frame, heaved the seventy-six-year-old man the masterpiece towards himself until it from the wall tore, and Saunière in a heap beneath the canvass backward collapsed.
As he anticipated had, an iron gate thundering nearby fell, barricading the suite-entrance. The parquet floor shook. Far off, began an alarm to ring.
The curator a moment lay, breath-gasping, stock-taking. Still am I alive. He out-crawled from under the canvass and the cavernous space for someplace to hide scanned.
Spoke a voice chillingly close. "Not move."
On his hands froze the curator and knees, slowly turning his head.
Only fifteen feet away his attacker's mountainous silhouette through the iron bars, outside the sealed gate, stared. He was broad and tall, with ghost-pale skin and white hair thinning. His irises were pink with dark-red pupils. The albino drew a pistol from his coat and the barrel through the bars, directly at the curator, aimed. "You not should have run." His accent not was easy to place. "Now tell me where it is."

I can't see that it makes a noticeable improvement. There are actually fewer word-order changes than you would expect, since Brown uses many fairly simple main clauses and relatively little subordination, which results in fewer differences between the word order of Old English and Present-Day English. Of course switching around word order can do nothing for the idiotic semantics of the description here.

In case you want to start writing like an Anglo-Saxon yourself, here are my rules. They are a vast oversimplification of OE syntax and turn what are really just tendencies into absolute dicta, so don't take them too seriously. We're aiming for the flavor, not complete accuracy. In the case of constructions that simply don't exist in OE, such as strings of multiple auxiliaries, we simply apply the basic word-order rules without trying to translate into something that would be more accurate.

Be warned that to apply them you will need a decent grasp of basic syntactic terminology.

[Update 12/06/2007: minor wording changes to clarify a few points]

1. In main clauses, the finite verb usually goes in second position. In other words, when the sentence opens with a subject, use the PDE order of subject-verb (SV). But when the sentence starts with an adverb, prepositional phrase, etc., the verb appears after that initial constituent, and the subject comes next.

For example, "Then Janice left home" becomes "Then left Janice home."
(NB: In a more restricted way, this still happens in PDE, cf. "Down came the rain and washed the spider out.")

Note that only the finite verb moves, so if there's an auxiliary, only move the first auxiliary, not the whole verbal group:

"Now Janice has explained her position" becomes "Now has Janice explained her position."

1a. A coordinated main clause (one introduced with "and") uses the above order (V second) if it starts with an adverbial, otherwise it is verb-final, as in rule 2 below.

2. In subordinate clauses, put the verb in final position within the clause.

For example, "After he downloaded the music from the Internet" becomes "After he the music from the Internet downloaded."

2b. When the subordinate clause has an auxiliary and a main verb, move the whole group to the end, but put the auxiliary last.

So "When you have finished your homework" becomes "When you your homework finished have."

3. Unless you already have VS word order as the result of rule 1 above, move direct or indirect objects consisting of just a pronoun before the verb.

"She likes him" becomes "She him likes."

4. Eliminate any use of DO in questions and invert the main verb:
"What did you see?" becomes "What saw you?"
(Questions like "What have you seen?" remain unaffected.)

5. Whether a clitic ('nt) or a separate word, move the verbal negator "not" to immediately before the verb over which it has scope, deleting DO if present.

"I didn't see George" becomes "I not saw George."
and "I haven't seen George" becomes "I not have seen George."

6. Put other one-word adverbial modifiers immediately in front of the word they modify:
"Joanna brought her toys upstairs" becomes "Joanna upstairs brought her toys."

7. When a name has an appositive element like a title or a descriptor, put it after the proper noun:
"President Clinton" becomes "Clinton President"
"The new senator Baxter" becomes "Baxter, the new senator,"
"Los Angeles County" becomes "County Los Angeles"

8. Delete the dummy subject "there" and move the complement in front of the verb:
"There will be snacks at the reception" becomes "Snacks will be at the reception."

9. Move later stacked adjectives after the noun and join with "and." (If there's only one adjective after the noun, you can omit the "and" if it sounds better.)
So, "my poor, tender child" becomes "my poor child and tender."

10. Change all synthetic genitives (i.e., possessives formed with "of") into inflected ones. (This one can lead to some misleading changes in meaning, so you can treat it as optional if you want):
"the end of the matter" becomes "the matter's end"

11. Split coordinate constructions unless they're already at the right edge of a clause.
"On his hands and knees, the curator froze" becomes "On his hands froze the curator and knees"

12. Shift heavy elements such as complex phrases towards the right edge of their clause. This principle plays a role in several of the rules above and can override some of the others, especially verb-final clauses. In particular, clauses, infinitive phrases, and the like should not appear in subject position.

So "That his prose is appalling did not affect Brown's sales" becomes "It not affected Brown's sales that his prose appalling is."

For extra credit:

Imitate OE word formation. Specifically:

Put particles from so-called "phrasal verbs" in front of the verb and attach them with a hyphen:
"She looked up the number" becomes "She up-looked the number."

Turn adjective phrases with PP modification into compounds:

"Eager for glory" becomes "glory-eager"

Use negative concord:

"No one lived better than he did" becomes "No one not lived better than he did."

For intransitive verbs that reflect a change of state (go, come, rise, fall, etc.), use forms of BE rather than HAVE to form the perfect:
"Mary has come" becomes "Mary is come"

These are just the points that occurred to me while working on the example above. I didn't systematically work my way through Mitchell, or even CHEL (although I did quickly glance at the latter). Additions or correction are welcome.