After reading yesterday that Bornakk confirmed a "gear reset" (which is not actually a reset-- more on that in a sec), reader John had an interesting thought about using current high-level instances (Hyjal and BT) to attune players for future high level instances, so that neither the gear or the content would go unused. Which is kind of happening already-- it's all but confirmed that Naxx will be repurposed in the next expansion. But that just suggested something else to me: what if, rather than worrying about a "gear reset." Blizzard actually made the current endgame mandatory for entry into Northrend? What if you couldn't move on without doing all the current content?
That would ensure that you got the use you needed out of the gear you had now, and it would also make sure that everyone coming through saw everything-- your guild would have to down Archimonde to enter into the next 10 levels.
Now, it's pretty clear that won't happen, because Blizzard is much, much more inclined to make things more open rather than put more requirements on their new content. But you have to admit that it would solve the problem-- either run and experience the content, or don't move on.
Finally, other readers did note one more thing about the "gear reset" and that's that it's not actually a reset at all-- much of the highest level gear won't be replaced for quite a while (I was still wearing my Tier 2 helm when I hit 69, and people wearing full T6 right now likely will keep their gear even through the starting quests in WotLK). But that still doesn't change the fact that Blizzard is basically running two gear paths here-- either fight in the raids for the high-level armor now, or just pick it up later when you enter Northrend.