Crisis Coverage: Not All Banks Are Banks

It has been pointed out to me that nearly everyone discussing this crisis is referring to things like "banks need capital" or "the Fed increased liquidity available to banks" or "the financials are in trouble", yet no one has really explained why Bank of America and JP Morgan have been stable while Lehman and Bear were in trouble. Morgan Stanley is not in merger talks and even the great Goldman Sachs has rumors about it flying. Why are some stable and others disappear overnight?