Obama also said this...

"If I am the nominee, then I will make sure that our people talk to John McCain's people to find out if we are willing to abide by the same rules and regulations in respect to the general election." But, he added, "it would be presumptuous of me to start saying now that I'm locking myself into something when I don't even know if the other side is going to agree to it, and I'm not the nominee."

http://www.washingtonpost.com/wp-dyn/content/article/2008/02/15/AR2008021503639_pf.html