Sorry to disagree, but for myself I really hope they will keep the exalted tabards and the couple dungeons for rep thing.

Why? Having thrallmar, sha'tar etc tabard should "mean something".
Also iirc BC tabards are last of the old type of "exalted to get".
If every tabard would be given by mere friendly stuff like 30 tabards achi (that comes in 4.1) doesnt seem to mean anything at all, just get 30 reps to friendly and get some honor for pvp tabards (not AB rep tho)..thats couple quests for every faction really while levelling (it should be sort of same way as 40 exalted IMO but less still slightly grindy).
I know it can be pain in the ass to get rep for those BC factions but what else would you grind them for if not tabards?
Surely you are not using epics they give out, since you are going to northend. You wont be using those head/enchant resistance enchants. Nor the pvp set of blues - most likely.
Therefore its tabards that, atleast me, will go for when I did BC to exalted couple months back so I can use different colors that fits the gear I use.