According to the FT:
The head of equities at one of the UK’s biggest investors said the repercussions should AIG fail were “potentially bigger than Lehmans. It is too big to go bust. If it does, we will be eating baked beans out of a tin.”
Alarmist perhaps, but the article is worth reading: it does appear that AIG, like Fannie and Freddie, is too big to fail.