Modern scientific polling, especially in off-year elections, is only slightly more accurate reading goat entrails.
And significantly less accurate than crystal ball gazing.
But, seriously, the Libertarian candidate clearly cost the Republican troglodyte the election. This is not a good sign for Democrats in the state, right now Virginia is not in play in 2016. Establishment Republicans will see this result as proof they need to widen the tent. Tea Partiers will see the result as more evidence of RINO treachery, mainstream Republican donors didn't flood the state with money supporting Cuccinelli's campaign, as well as libertarian betrayal. They will redouble their efforts to purge the Republican Party of oldthinkers.
The current meme, particularly from the news networks, is that Chris Christie is the clear favorite for the Republican presidential nomination. I doubt it. First, the Tea Partiers see him as Public Enemy No. 1, some are blaming Christie for the Virginia result because he didn't campaign for Cuccinelli. Mostly, though, I don't think Christie's "in your face" style will play well west of the Delaware River. Christie will have early money, will probably under preform in Iowa, do well in New Hampshire, and suck eggs elsewhere.