Webb can have some appeal but he is going to have to deal with a couple of issues. One is that he voted against the Comprehensive Immigration Reform Act of 2007, essentially being the deciding vote killing the Bill (which puts him to the right of GW Bush). The other is that he has spoken out against affirmative action.
The immigration vote might be a concern, but its good that we have a Democrat running who isn't for race-based affirmative action which is one of the wedge issue the Right has exploited so successfully.