Also keep in mind that Kaine, Warner, and Webb are moderate Dems, while Obama and Clinton are liberal democrats. Obama's ceiling in VA will be 48% of the vote.
Virginia has yet to be contested on the national level as a true battleground. This is the first time in years VA's even been considered a swing state. It will take more than one election cycle to solidify that trend to the left enough to go Democrat, especially against McCain. For example, take New Jersey and New Hampshire...solid GOP in 1988, swing states that leaned to the right of the national average in 1992, but the national margin was great enough to swing them barely Dem, 1996 both were left of the national average. In 2000, NJ was solid Dem wheras NH swung back right in 2000, before making its assumed journey into solid democrat territory to stay.
However, if Warner had gotten the nomination this year, Virginia would have seen a seismic shift to the Dems, maybe a 15% shift or greater in terms of the national average
Webb isn't a moderate Democrat...
Also, I fail to understand why McCain has some huge appeal to Virginians that George W. Bush lacked.