Rift may end up claiming the record for most bloggers who are not playing the beta events because they have already pre-ordered. I don't know if there's an official list, but I've definitely read this sentiment a few times since the betas launched. (Syp's contribution was the easiest to find.)
For me personally, not playing the betas is mostly due to being relatively busy. We're sitting about three weeks out from the game's "head start" launch, at which point we'll be allowed to actually keep our characters.
The main thing that I would be doing if I did clear out time for Rift right now would be test driving possible builds. Then again, it is still a beta, and things could change before launch. For example, I heard some complaints on the Rift Reporter podcast about mana regen issues, and how they've been improving during the ongoing testing. I don't want to miss out on a potentially fun class because it wasn't quite finished yet when I got around to trying it.
The game is getting down to its last few beta builds, and hopefully things are starting to settle down. In particular, we're all better off if the way that characters work can be settled before launch, rather than afterwards. It's just an interesting artifact of Trion's decision to run short beta events rather than the traditional 24/7 beta; each build/event is made to seem like a major milestone in its own right, which may magnify the impression that big changes are still coming down the pike.