Oh yes, I have this one. I keep getting killed! (“Be ashamed!”) 
In Lauren Willig’s “Pink Carnation” series, Jane Austen herself is a minor character in one book (a friend of the female lead in Mischief of the Mistletoe, I think).
That, by the way, is a fun series. Told from the point of view of a modern-day historian (from America) who is researching Napoleonic-era spies like the Scarlet Pimpernel (in the series, portrayed as a historical character).
I read somewhere awhile back that Patrick O’Brian gave his hero Capt. Jack Aubrey the same initials as Jane Austen because he enjoyed her books so much.
Slight bump because I found out that someone I know (a high school English teacher) has been maintaining a list of Pride and Prejudice variations on her blog for some time. She doesn’t provide summaries, but she does mark books she recommends.
Oh, awesome! Thank you! 
Bumping the thread - today’s the bicentennial of the first publication of Pride and Prejudice: http://www.cnn.com/2013/01/28/world/europe/pride-and-prejudice-200th-anniversary/index.html?iid=article_sidebar
AFAICT I haven’t seen anybody mention Joan Aiken’s Jane Austen sequels. The only specifically P&P-connected one is “Lady Catherine’s Necklace”, but I haven’t read it and don’t know whether any of the more major P&P characters appear in it.
That would make him Twice Knightly. (I’m here all week)
There’s also a youtube series set in the modern day. The Lizzie Bennet Diaries.
I’ve read the first one, Pride and Prescience. I agree about the resolution, and frankly disliked most of the book. However, if you can find it at the library, the first chapter works very well as a stand alone short story and is very funny. Elizabeth Bennet plays hardball.
The same author has a few titles: Elizabeth Aston
Mr Darcy’s Daughters was due back at the library before I finished it and I wasn’t able to renew it because someone had a hold. I didn’t go to the trouble to place a hold on it myself to read the rest. I’ll read it eventually.
I’ve read a lot of what’s out there. I’ve enjoyed a few of Abigail Reynolds’ titles but she does veer into bodice ripping territory which ends up disappointing me.
I was given three of Carrie Bebris’ books as a gift and have yet to read any of them. Inspired by this thread I will make an effort to, at the very least, read the first chapter of her P&P.
Also going to give the Lost in Austen book a try. I watched the movie (series?) and neither loved nor hated it.