Ars Technica has posted that the iPhone definitly doesn't use an Intel CPU. Contrary to a lot of speculation that ensued from Jobs saying that the iPhone "runs OS X", this probably means the iPhone's browser won't run Flash. Flash is known to have a good number of hand coded assembly optimizations.
In a lot of ways it makes sense to leave Flash off, Flash video (via YouTube and on the television network websites) compete directly with iTunes. However, they don't want to advertise this, because the fact that it isn't compatible with YouTube and MySpace really kills the device for the younger market.
Watching the keynote I was looking for any sign that it did run Flash. Having read the transcript, I knew there was one place I would get an answer - on the Amazon homepage where they currently have Flash on the right side of the page. What happened when Jobs went to Amazon? He zoomed in on the left side of the page immediatly (away from the Flash element on the right) and navigated to the next page before the homepage was done loading. Why would he do that if he wasn't trying to avoid showing us that Flash didn't work?
This isn't to say that Flash won't ultimatly ship on the device; it's still a number of months before the iPhone ships, but it's probably not working on it as of right now.
Update: David Pogue confirms that the iPhone doesn't run Flash.