(1) Does John McCain try to turn Obama's decision into a cri de coeur? The media will not help him; instead of focusing on Obama's circumstance-based decision to go back on his implied promise, they'll probably take Obama's side. It's true that voters generally don't pay attention to this type of thing, but if McCain puts it front and center on his mantle, will they?
(2) The potential money gap in the general election is huge -- Obama could raise as much as $300m, and the McCain campaign/RNC budget team doesn't anticipating spending more than $150m.
(3) The McCain campaign did not expect Obama to announce his decision this early, and so they were caught unawares.
(4) How will the "reform" community react?