I'm still DL'ing... I assume its the whole game, they say that they want you to participate in all aspects of the game, and to complete the story line for at least one class. Guess which class I'm gonna choose? 
EDIT-
If its a weekend thing and cuts off, I'll be sure to post back. Do you recall what your emails and testing pages said?
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EDIT2-
From the testing FAQ:
How long is each testing session?
The duration of each testing session will vary depending on what content or features are being tested.
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I might have jumped the gun on posting this... Checking the tester forum, it looks like the stickies go back to March. I thought that they had JUST started the beta seeing as how I signed up for it the day it was announced and heard nothing since (until now).
In any case... YAY!... I get to play SWTOR. 