This is big news. The Romney campaign and Cross Roads are pulling out of Michigan and Pennsylvania, after 5 months of big spends with no results.
Remember that Romney has two home states: Massachusetts, where he never even tried to compete and Michigan, where he has spent big and is now abandoning. You can't win the presidency without winning your home state. Ask Al Gore. Had Gore won Tennessee, Florida would have been irrelevant.
I'm guessing both groups will focus spending on Ohio and Florida. Romney has been even further behind in Ohio than in Michigan, but if they abandon Ohio, they concede the contest and that's not happening.