As yet these items seem to be purely cosmetic, offering the look of now-lost sets. There's no sign yet of Tier 3 (original Naxxramas gear) or BC Season 3 Vengeful PVP gear right now, but who knows? This is certainly a step in the right direction for that happening. I'm pretty excited, let me tell you. While my main warrior has the sets he wants, one of my alts would look fantastic in Battlegear of Heroism.
Brace yourselves for what could be some of most exciting updates to the game recently with patch 4.3. Review the official patch notes, and then dig into what's ahead: new item storage options, cross-realm raiding, cosmetic armor skinning and your chance to battle the mighty Deathwing -- from astride his back!