A poll out of Public Policy Polling has McCain and Obama tied at 45% each. Last month, PPP showed Obama up by 8%. Link
I can't think of one state that Obama has improved his position in, polling wise, since he got the nomination, can you? Colorado has been trending McCain, with two polls last week (Rasmussen & Rocky Mountain Newspaper) showing that McCain has actually taken the lead there. Missouri has gravitated into a lean McCain state from a tossup state. This is reminding me very much of 2004.