How longer can I use my gearsFollow

Tomorrow, the wraith of the lich king will be patched in all of korean server
I`m very interested in levelling to join raid to Nax as soon as possible
I`ve got a full of tier6 gear of retribution and got archimond droped two hand sword
(2300 ap without buff 35%of crit 5%exper 8%hit-rate)
Can I use my gear to the heroic instance dungeon
I am very curious how fablouse adventures are prepared for me.
and I am worried about my server race ratio
Because of poor server management, my server has 1:2 ratio of aliance to horde
I couldn`t do a quest in outland and Khueltaras(Sorry spelling is so poor :) )
Horde lorgues and warlocks used to gaze me anywhere( scared)
In northrend, is it same aspect to me It will be horrible
thank you for reading my poor grammer

I replaced my T4 tank shoulders in UK at 70, but it was a very small upgrade.

My S2 weapon and badge pants haven't had anything even close yet. Ah, but I'm only 71 now. There's DKs running around higher level than me.

Again though, those revered items will be at least level 78, if not 80, required to use.

I doubt anyone that had been into Heroics/raids pre Wrath will find many upgrades the first have of their leveling career in Wrath. Alts with lesser gear may find more upgrades earlier on, but my gf's Mage hasn't found any upgrades yet, and she didn't have all that great of gear pre Wrath to begin with.