Why would they continue to make them when they could get you to buy a whole new crank AND BB by stopping? They do still make them, but all of their higher-end cranks are Hollowtech II and that technology is migrating all the way down the line. Sorry to be cynical, but I think it's only a matter of time.

An LX Hollowtech II crank (w/BB of course) is ~$150. It's not a good crank, it's a great crank. You could probably find "last year's model" a lot cheaper.

edit: don't get me wrong. Shimano BB's are generally of very high quality. So if you have at least a middle-of-the-road Octalink BB, it should last for many, many years. Long enough for Hollowtech II to become obsolete!

edit 2: you may also guess from what I've written what I think of Microsoft!