United Airlines (UA) is now in merger talks with US Airways (US), after having been rejected by Delta Air Lines (DL) and Continental Airlines (CO). http://www.usatoday.com/travel/flights/2008-04-28-united-us-air_N.htm?loc=interstitialskip
There's a reason Delta and Continental jilted United: UA's finances are in the toilet. No airline management team with a responsibility to their stockholders should want them as a dance partner. Does US think, like with the US Airways/America West merger, that they can draw in outside capital on a merger? That's the only way this is even sane. However, with oil prices where they are, I don't know who would want to put their money into a weak airline now.
The best thing that can be done for the airline industry and (most) travellers is to let UA sink. The breathing space that would open up would allow other airlines to pick up UA's passengers.