Well I would think they would honor warranty on older products. Infact, I think they should go out of their way to DEFINITELY take care of even well out-dated MK products of old, too! But I guess we'll see.
Companies unfortunately do go under from time to time. It's the nature of things. I do, however, hate to see co's that otherwise make excellent products go under. But then I'm that much more pleased to see em come back! (I mean, would you rather have some other company come fill their void, offering inferior product? I wouldn't.
Beyond the politics and uncertainties, I've always thought they made very well built, solid, good sounding products for what they were designed for. Certainly, the dependability factor was VERY GOOD, IME! I wouldn't hesitate to buy or sell the products in the right situation.
Hope they do well, and come back strong.