My impressions from the weekend beta a few weeks back...I played a Bounty Hunter Mercenary to 15 and a Jedi to 8 or 9.
I wasn't feeling it at first. It felt like a generic MMO with VA included. The voice acting is nice when the story is somewhat compelling, but listening to an NPC go on about why he needed me to "pick up x number of supply bags" or "kill x number of dudes" for ancillary reasons was annoying. One of the first things I did was to turn on subtitles and skim through most of the dialogue. I noticed a bunch of people in chat asking how you skip dialogue, so I wasn't the only one. It wasn't until the main storyline picked up that I appreciated the VA.
The companion feature is a nice touch. You can customize their play-style a bit to your preference depending on the companion (i.e. more dps or healing), and it's nice to have them participate in your conversations every now and then. Despite their efforts to offer customizations, it's still silly to see everyone in your class running with the same companion.
The space combat was forgettable, the one flashpoint I tried was fun, and the PvP ball-game was alright; once I figured out what was going on (the announcer is annoying as hell though). The visuals are much improved, though I was never a fan of the style anyways. The controls, options, frame-rate, and bugs were exceptionally good considering the game is still in beta. I've played release games that were worse off then this.
I was a little skeptical about the game, but the beta has sold me for a few months at least. After that, how long I stay depends on how the end-game content feels, and how quickly they can provide new content (I worry that having to fully VA everything is going to make content updates slow).
I had intentions to go Trooper before the beta, but the BH abilities are so much cooler in comparison. Jetpacks, missles, lasers...etc. I was also considering tanking, but I might switch to heals/dps as a Commando or Mercenary. Something about healing while wielding double-blasters or a huge cannon is hilarious to me. Plus, I noticed they get an ability that works like "earth shield" from my beloved resto shaman.