Bare mounts yes, but bear mounts no way.
Very rarely (as I recall) have items been taken out of World of Warcraft. However, if you want to get your bear mount from Zul'Aman, you better act quickly. Rumors are swirling as to when the next patch will come out (as early as next week?) but according to Zarhym (Blizzard poster):
"This item [bear mount] will no longer be available with the release of the next content patch. Mind you this patch will happen before the release of Wrath of the Lich King."
For those uninitiated, the bear mount is a loot drop from Zul'Aman if the group completes the whole instance within the time allotment (a fairly tough accomplishment). Zarhym must be serious about the bear mount going away because he posted it twice, both here and here.