The Washington Post ran an interesting story this morning (here) about the surprising absence of any boost for climate legislation stemming from the BP oil spill. The story notes that, in the past, major environmental catastrophes have led to significant legislative action (e.g., the Santa Barbara oil spill led directly to the enactment in 1972 of the Clean Water Act). The article surmises that the poor state of the economy might be partly to blame.
In any case, time is running out for the Senate to pass climate change legislation before the November mid-term elections. After those elections, enacting even semi-serious climate legislation is likely to be much, much tougher, with Republicans expected to pick up a substantial number of seats in both houses of Congress. If climate legislation is not enacted this summer, then I would expect to see any real movement until after the 2012 presidential elections (and not then if Obama fails to win reelection).
Without US legislative action, international efforts to adopt a successor treaty to the Kyoto Protocol before 2012 are probably doomed. The best that can be hoped for would be an extension of the Kyoto Protocol, until such time as the US proves itself to be a serious partner in climate negotiations.