I have actually went to my local sprint store today to play around with the display unit. Honestly it is a very good smart phone overall but it is deffinately NOT an "iPhone killer". The pre is much smaller than the iPhone and more compact, however it doesn't feel as "solid" as the iPhone. The cool things about the pre is that it has a beautifull screen, loud speakerphone, web os is very fun to use with cards and multy tasking, has a good camera. The bad is that the keyboard is kind of crappy and uncomfortable to use, the os is often laggy which is the biggest problem I found with the pre. After using a pre I understand why apple went with running one app at a time, at least for right now. Pre's web os overall doesn't feel nearly as snappy as iPhones os. The only thing that runs nearly 100% smooth is contacts list, and email. Everything else is little to modorately laggy. I'm sure sooner or later palm will improve all the bugs.
Over all it's a great phone and very suitable alternative to an iPhone. But it is deffinately not an iPhone killer.