Hot on the heels of the Patch 3.3.3 PTR patch notes, Blizzard has activated character copies for this phase of testing. While the realms aren't up quite yet, and neither is the client, you can definitely copy your live characters over to Broxigar (PVE) or Anasterian (PVP) for impending testing.
A few things to bear in mind: if you're excited to try out the new Ruby Sanctum raid, that content isn't going to be in this particular patch. There might be indications of it, maybe some quests or data, but no instance itself just yet. But, since there's no raid content, this means you can also copy over premade level 80 characters -- the perfect way to test out all those new PVP changes.
Well, what are you waiting for? Go make your evil twin!