We'll have to wait and see if it becomes more useful, but as of WotLK standards it's nothing more than a dps boost.
I don't really think you're going to be "expected" to bring it like you would be "expected" to bring something like TSA. I really can't see any raid leader saying "Oh, sorry, MM hunter, we're not gonna bring you on this raid because you can't interupt once every 30 seconds."
See now you're contradicting your own logic. If it's a utility talent, it's something that some people take and others don't. So if raid leaders "expect" you to have it, that basically makes it mandatory, and then it's not really a utility talent anymore.
Are some MM hunters going to take it to be more useful? Yes probably. Are a lot of MM hunters also going to skip it to do more dps? Yes, most likely. I dunno about you, but most dps that I've met (including myself) are a bit of dps crazed. It's the reason that you don't see hunters running around with Hawk Eye, for instance. Nice utility talent that can be very useful in certain situations, but you have to sacrifice dps talents to get it, so no one does.
Go to the current beta talent build and make an MM spec. You'll find that you can fit all your points and then some into dps increases in some form or another. I'm going off the current beta build, because I can't exactly know what the final trees are going to look like.
If someone doesn't have their SilS macro'd to all their other shots on fights like marrowgar, saurfang, fester, rot, putri, etc., they're certainly not a "pro." The only fights that really warrant un-macro'ing it are deathwhisper, dreamwalker, and LK, and even then it's far from a necessity to un-macro it.