Here’s a list of all World of Warcraft: Wrath of the Lich King installers:
The download is 2.04Gb (on a Mac), I haven’t started the download on a Windows yet.
And yes, you will still need a beta invitation before being able to login!
You’ll find me under Tuinslak or Isazi on the EU beta realm.
As for the character copy, it was done within 10 minutes. Just 5 hours left on the download. 🙁
Edit: same size on a Windows – 2.04Gb. The download contains the setup.exe and the installer.app, so you should be able to copy it to any OS.