Of course he won't. Time magazine is preparing their 8th Obama cover as we speak. Why would you expect him to get any buzz?
The only way announcing his choice tomorrow is going to be effective is if it's someone unexpected, like Joe LIEberman or Colin Powell. Powell wouldn't take it were it offered, IMO, and LIEberman would be radioactive to the Christian Right.
While Lieberman wouldn't please the Religious Right, it won't stop them from going to the polls, and they sure as hell aren't going to vote for Obama. If anything Lieberman helps McCain pull in the undecided/moderate vote.
Trust me, I was born into the Religious Right and my parents are still members. They hate anyone who is a Democrat and always show up at the polls to vote straight Republican. Lieberman isn't going to change that. Not that any of this matters, I don't think McCain will pick him.