What do you mean by "3D bubble?"
I thought you meant the half-circle reflection, but the current versions both have that:
http://www.twitterholics.net/wp-content/uploads/2008/02/iphone-screen.jpg
So I'm not sure what you mean.
EDIT: OHhh, you mean the phone doesn't have a drop shadow on it? Hmm, I'm wondering if all the icons will be changing, but only the text-message icon was changed in the Beta because they had to do it. So perhaps everything else will change to match it when 3.0 comes out for real.
Dunno. Just a wild guess.