That's crossed my mind, too, from time to time!;-) Given Anielka's theory that, especially for P&P, the people's names are from Jane's own ancestors, I think its entirely possible that there's more family jokes in there than anyone outside the Austen family has ever spotted. Don't you wish we knew for sure?
Bourne, by the way, is a pretty common place name in Hampshire. Can we make any connection between Longbourne and Selborne or Winterbourne, do you think?