Yes, that would be a close election in my opinion. McCain's an ex POW who supported Bush on Iraq. That could work for him or against him. He's also not as conservative as Bush on domestic issues, which hasn't endeared him to the right wingers. But the way I look at it is, if Rush Limbaugh doesn't like him, he must be alright in my book.
I do think that Obama is a much more dynamic speaker than McCain, which would win any debates the two will have.
I do think that these two are the best candidates in either party, so as they say, stay tuned.