BG/Arena for tanking gear is a nay. I have seen some good tanks with the Arena shield tho... so maybe not all the items are just for dps lol.
BG epics will be ok, until you can replace them with better PvE items. PvP gear tends to lack the +hit needed in PvE, but has excess in +crit lol. I believe if you're going DW Fury build the lack of +hit won't effect you much. If you're 2H MS Arms build (like I currently am), the lack of +hit will kill you.
Two routes to go IMO:
1) Respec to Prot, and just tank every instance just about. Get rep that way, and pick up epics slowly but surely. After so long, you'll be heroics ready. Getting into heroics as a DPS Warrior is very very rough. Having you, that's one less sheeper, banish, etc.
2)Continue up the BG path. Then hit Arenas. For a DPS Warrior there are VERY nice things in there. Yes, still kindda lack the +hit, but in T5 content I'm using the helm, and gloves (until I get better gloves anyway).
Oh you can check out wow armory and look for upgrades, or check
MaxDPS site. It'll give you a little check list on what to look forward to.
Good luck.
*Edit* just noticed you said you're Arms. In greens I don't blame them for not wanting you lol. No offense, but Arms is more demanding than Fury. Our hit cap is 142, Fury is what? 43? Something crazy low. Arms also does not get super dps'ing until T6 content (from what I read). In raids I'm more used for the 4% to all melee attackers debuff on the mob, then I am for DPS'ing lol. Don't get me wrong, I'm up around 6 or 7th on the WWS charts... but no where near the top...yet.
Edited, Sep 25th 2008 12:40pm by GYFFORD