$10 says Friday's Apple press conference is the announcement about Verizon, to — in the words of Don Draper — change the conversation.
http://twitter.com/danrubin/status/18565906020
While probably not too likely, it would be an interesting move on Apple's part none the less.
Besides, if they're going to announce a Verizon phone then they're effectively announcing a new model; the GSM iPhone 4 obviously isn't compatible with Verizon's network. In my opinion this is the kind of thing you'd do at the launch of a new iPhone generation, not just a few weeks afterward.
Absolutely not. If a deal with Verizon were announced at the launch, it would have completely overshadowed all of the engineering effort put into the phone. It would be known as the "Verizon iPhone". This way, out of the spotlight, it leaves the iPhone brand unharmed.