The polls mean nothing at this time. The vast majority of voters aren't paying attention to this year's election, and won't until after Labor Day.
I'm not discounting Laz's thoughts, but remember this:
it will all crystalize the last weekend before Election Day. The average voter will ask themselves, "do I really want another 4 years of Obama?"
Through that examination, they'll be reminded of inflation at the grocery store, pain at the pump, crony capitalism (green energy - Solyndra), 15% effective unemployment, a few more vacations by Michelle, and the likelihood the debt limit has been reached ahead of schedule...again.
If the Pubbies/Mitt can focus on the economy, and the spectre of an unfettered Obama in his second term, Romney should win 350+ EV's.
Sadly, moments after I posted, Santorum dropped out. Correct me if I am wrong, but it seems Romney is the GOP nominee. That is profoundly discouraging to me, and will take some time to digest.