Would I be able to disable the Touchwiz? Also like on the Nexus One or mytouch slide 3g would I be able to see the weather, for example if it is raining will it begin to show a rain animation? Or does this feature get overshadowed by touchwiz?
Not sure why everyone calls it TouchWiz. Another piece of misinformation being spread around the web, I suspect. TouchWiz is Samsung's modified UI for WinMo 6.5, not Android. Samsung's press releases call the ANdroid UI "Smart Life".
I'm not a big fan of it either. I suspect you will not be able to turn it off, but XDA Developers should allow us to drop plain vanilla Android 2.2 onto the Vibrant not long after its release.