In case you were wondering, there will be premade characters for the 2.4.3 PTR before all is said and done, according to Hortus. There's no word for sure on why they're needed, what gear they'll have, or when they'll come along, but they'll be here. You'll need an account that had Burning Crusade activated before these PTRs went live, and when the time comes, you'll be able to sandbox it up with a fresh new premade while you help test the patch.
This phase, says Hortus, is also not intended for testing Season 4 gear, since it was already tested on a previous PTR. Besides, with 4 days left until Season 4 goes live, the 2.4.3 patch won't be on live servers until Season 4 is well underway. That said, it looks like most (but not all) of the Season 4 gear is still on the PTR right now, so if you want to go check it out, you can fly up to Area 52 on the PTR and check out Big Zokk Torquewrench's wares. Of course, you can also expect us to give you all the Season 4 news you need in the next few days here at WoW Insider as well, including gear guides.
Also, Mages and Warlocks are reporting that their self-buff armor spells are now no longer dispellable on the PTR servers. That's a nice chunk of mana you won't have to waste recasting after a stray Purge in PvP. We'll be watching the PTRs for more undocumented changes, oddities, and happenings, so be sure to keep it here for the rest of the testing cycle for all the news and analysis you'll need when the patch goes live.