Barclays and BofA have bailed out of any attempt to salvage Lehman Brothers. Special trading sessions are happening now so other firms can try to net out their exposure to Lehman in advance of an expected bankruptcy filing before open of market on Monday.
The big stumbling block was the refusal of the federal government to provide any guarantee against Lehman debt and the refusal (or inability) of any bank to put money into Lehman.
No one really knows what the repercussions of this will be, except that this is a seriously big deal.