I wouldn't be at all surprised to see McAuliffe run unopposed for the nomination. It looks like he's been quietly running since Deeds lost and has probably won over the major donors and opinion makers. The fact that in the wake of his announcement no one notable came out to say they were even thinking about running is pretty telling. One would want to stunt his momentum as quickly as possible.
As for Webb and Perriello, it seems like Webb is done with electoral politics. Perriello's passion seems to be on international issues, a subject that is not particularly suited for a stint as Governor. He has a pretty influential job right now in D.C. anyways.
As for the general election, there are obviously problems with McAuliffe (past campaign folies, reputation as a partisan, lack of enthusiasm from party activists) but he has a fair amount of private sector experience as well. He'll portray himself as a moderate Democratic businessman and with enough money and smart tactics he'll probably make a race out of it.
I will now accept my accolades