Main problem with KMart is that they don't have a clear identity - WalMart beats them on price almost every time because of their greater distribution efficiency, and Target appeals to a different customer demographic (they used to describe themselves as "your upscale discount store.") Target and WalMart can happily coexist, but KM can't defeat either of them. What's KMart doing to do to give themselves a clear identity? There might be a window of opportunity to emphasize the Super-K grocery/discount store combos, but grocery is a ruthless business.
If I was going to do a trade on the KM situation (having already missed the chance to buy Target before the bankruptcy), I'd short Martha Stewart - I don't think WalMart will want the line, and Target already has name-brand linens and the Michael Graves line of kitchen stuff.
As for airlines, I already own some, but I wouldn't touch UAL with a ten-foot pole, except on a VERY short-term basis - too many labour issues, including a mechanics union that lives in an alternate reality. I have some sympathy for them (they are way beind mechanics at some of the other majors), but there's no way the airline can meet their demands. I don't even think the airline can afford the mediator's recommendation, which UAL management has said they would accept. They've already had a PEB on this one - it could come down to a strike, and I wouldn't be surprised if travel agents are already booking away from UAL. I think UAL will survive (unlike US, which is in a race with America West to see who'll tank first), but there could be a Chapter 11 in their future.
With airlines, unless you're strictly a short-term trader, good management is the key - CEOs like Herb Kelleher (Southwest), Gordon Bethune (Continental), or David Neeleman (JetBlue - I can't wait for the IPO!) In the last decade, UAL has consistently been one of the worst managed companies of its size in any industry. The new CEO may be able turn this around, but there are so many issues - high costs, labour strife, loss of full-fare coach passengers to AA, etc. - that there are better investment opportunities elsewhere.