Although Steve Ballmer did not, as some outlandish rumors asserted he would, make an appearance at WWDC 2010 today, Steve Jobs did say something important concerning Microsoft's search engine. Jobs indicated that Bing will now be an official search option on the iPhone.
This could constitute a significant win for Microsoft in a couple of ways. It and Apple haven't always been on friendly terms, of course, and Apple and Google used to be extremely close, so the fact that Apple has started to accommodate Bing might mean tensions are thawing.
(Skeptical? Okay, but consider that the Justin Long-John Hodgman Apple-PC ads have been retired, too.)
Then there's the simple matter of attracting users. If Bing's presented as an easy-to-choose alternative to Google rather than left off the menu, it stands to reason that more people will give Bing a shot. And according to Joshua Topolsky, Jobs even said during his keynote, "Microsoft has done a great job on this. Check it out, it's kinda cool."
Note that Google remains the default search engine on the iPhone, though, so Apple and Jobs don't appear to have had a total change of heart regarding the search giant.