I started playing during BC, so Wrath was my first new expansion. I hadn't been all that concerned with the beta testing phase, since I didn't have access to anything until 3.0 hit the PTR. I did, however, check that out.
When the Cataclysm beta testing was going on, I was much more curious about the forthcoming new world and the exploration thereof. I did wish that I was there, especially since I had ideas about places to go and explore and things to test.
Pandaria will be different. I already know that I'm in the beta, due to the one year commitment. I go in with no expectations. I've been refining my perspective over these past months, gaining greater understanding of a variety of genres. Hopefully, these efforts will make my voice worth something. This will be my big test and I'm still preparing for it.
Yes, that's a good part of why I haven't been around. It was something I needed to do for myself.