Many months ago, the McCain campaign tried to push for a regular schedule of joint town halls that would replace the standard presidential election paradigm of three formal debates between the conventions and the general election. The Obama campaign suggested that it was interested, and back in those naive months of spring it seemed like the town halls were an example of where an Obama-McCain election, contested between two practitioners of politics-as-unusual, would break the mold.
Nope. The Obama campaign, realizing that it would be wise to do nothing that jeopardizes its lead, sent a letter to the Commission on Presidential Debates (the what now?) agreeing to three debates on September 26, October 7, and October 15. The campaign also agreed to the standard vice presidential debate.
The letter, written by David Plouffe, appears to rule out the possibility of more debates, saying, "Due to the late date of the two parties' nominating conventions, and the relatively short period between the end of the conventions and the first proposed date, it is likely that the four Commission debates will be the sole series of debates in the fall campaign."