....it isn't completely worthless. Some parties still have very potent single target players, and I still have very potent single-target enmity gathering skills. Most of the time, people attack the mob with the lowest HP, and that makes sense and can work perfectly well without marking.

I suppose what matters most is how comfortable you (as the tank) are with marking. I tend to do it as a force of habit, and it gives me the opportunity to think more ahead of time about what I'm going to do with each encounter. If you aren't used to it, it might just be a chore that isn't worth doing. I wouldn't expect any tank to mark, or think less of them if they don't.

One reason I bring it up is that some players seem to be annoyed at marking in 50+ dungeons. I'm not really trying to be bossy, and I realize it doesn't help as much as it did in <50 dungeons. But I still think it isn't completely useless. Thoughts?