SurveyUSA. 6/13-16. Likely voters. MoE 4.3% (5/16-18 results)
McCain (R) 43 (42)
Obama (D) 52 (48)
The internals:
Total Men Wom GOP Dem Other Whi
McCain 43 51 35 88 5 42 45
Obama 52 45 58 9 91 48 50
The Pollster.com composite score is Obama 49, McCain 42.6. I currently consider any state within single digits as a "swing state", but this thing is trending away from McCain.