From the article you linked to:
Quote:Mr. Obama laid out his proposal last month to the Federal Election Commission, seeking an opinion on its legality. The commissioners formally approved it on Thursday.
No promise to McCain was made. The NYTimes mis-characterizes Obama's communications with the FEC about the legality of his proposal, followed by McCain's "me too!" of the proposal, as an agreement between the two.
Obama hasn't made any agreements with anyone. He made a proposal and sought validation of it from the FEC.
That said, I'd like to see them both work within the public campaign financing limitations too. But, I think it is premature to be seeking agreements with each other since neither one of them have come close to reaching the delegate counts needed to be the nominee.
When it comes time to make such agreements, I want the agreement to include methods for eliminating 527s and other PACs from supplementing either campaign with their own ads whether they are negative or positive for the candidates. Without that, the candidates would be horses asses for agreeing to public funding limitations and not have a way to defend themselves against attack ads funded by others.