The only "raid dps buff" i can think of that is obtainable for a combat rogue would be Sunder Armor. Does any raiding rogue use Sunder Armor with any regualarity? I'm not top end raiding rogue, and I may be wrong, but I don't even have Sunder Armor on my UI. I've never seen a raiding rogue use it.
Assuming you mean Expose Armor: yes, there are rogues that use it regularly. With the rise of nonwarrior tanks, the value of Imp Expose armor is on the rise as well; many guilds use it on Brutallus, and I've used it on Twin Eredars as well. It's still certainly somewhat of a specialty ability - it's not used in all situations - but it does have it's place.
That is still purely a personal DPS buff, I am looking for something along the lines of a rogue Totem of Wrath or Ferocious Inspiration that not only buffs us, but buffs the rest of our party so that not only is there a reason to bring rogues for our DPS, but because we increase the DPS of everyone else. Think about it, right now in the melee group everyone but an additional rogue buffs the rest of the group, with the addition of Death Knights, you really need to increase the group synergy not just that rogues get, but that they provide in order to hold on to the 2-3 raid slots we have.
I think this is the real problem with rogue's right now. We, as rogues, do good damage assuming proper buffs... but we provide no buffs ourselves, nor any utility. Hence, with the advent of more and more utility meleers, the role of the rogue is increasing marginalized. On a melee friendly fight where you can bring all the utility meleers and a couple of rogues as well, there's no problem; but on a melee unfriendly fight, my experience is that the rogues are among the first to go. For instance, on my guild's first Brutallus kill, in terms of meleers, we had 2 ferals tanking, and then a Fury warrior, an Arms warrior, an Enhancement shaman, a Ret pally, and 3 Rogues - fine. But when it came time to do Felmyst and we wanted fewer melee in, the arms warrior respecced prot and tanks, and we swapped out the 2 ferals and 2 of the rogues, but kept the fury warrior, the enhancement shaman, and the ret pally. And with the advent of the Death Knight, I have to imagine that this situation only becomes even more pronounced. There are now 3 classes (DK, Warrior, Rogue) that can only be melee (either tanking or DPS); if you bring 2 or 3 of each, plus 1 of each utility melee spec (ret pally, prot pally, feral druid, enhancement shaman) you wind up with something like 10 or 11 tanks + melee, which is more than you're going to want on many fights - so something has to give, and the way things stand, I fear that that something would be rogues.
Hence, I think what is necessary - and what I hope they add - is some inherent reason why you want to bring 2 or 3 rogues to every fight. Just doing DPS is not enough anymore, when there are so many other melee classes that do competitive DPS plus provide raid utility. I think we really do need a raid buff or a boss debuff or some sort of reason why you might think about bringing rogues over utility meleers.
The other thing I'd note about the expansion talents so far is that it appears that they're making an effort to make all specs of a given class somewhat useful in a raid environment; the new talents seem designed such that you benefit from having a balance druid in addition to a feral and a resto; a disc priest in addition to a holy and a shadow; and so on. This is not currently at all true of rogues; most rogues are specced combat in the first place, and to the extent that you have ones that aren't (Mutilate, TSH, etc.) they're basically totally interchangable. So another thing they might be looking at doing is giving people a reason to specifically want a Subtlety rogue or an Assassination rogue in raids.