I have the 3.0 SDK (I was previously a developer) and I'm not even installing the 3.0 OS on my iPhone. Beta software is fine if it is a browser or what not, if Safari 4 dies I can shrug and either uninstall it or use Firefox. If I install iPhone OS 3 and find that it crashes on certain apps (it does) or doesn't work with some of my accessories (from what I can tell that is a common problem) then I'm screwed until they release the next beta. No thanks! I can wait until June. Besides, I can play with some of the features (like spotlight and copy/paste) on my simulator.