I'm not quite convinced, since that argument seems pretty much entirely predicated on the fact he's getting a higher profile lately, which might be more about stepping up pressure on the war as an issue as opposed to a potential build up to a VP nod.

There was also this interesting article where they asked the other 97 Senators what they would say if offered the VP spot:
http://thehill.com/leading-the-news/sena tors-say-whether-theyd-agree-to-be-vice- president-2008-05-12.html

Webb's response:
"I'm not really interested. That's all I want to say."

That seems pretty unambiguous. If he knew he was getting the nod I'd expect him to at least be a bit coy about it.