So I hit level 13 as a Conquerer, and I definitely still plan to pick up this game.
My comp is dual core 2.2 ghz, geforce 7600gt, 2 gigs of ram. Not the gretest PC for this game, but it runs, and is playable. I get pretty bad lag spikes at times, where the game will be unplayable for a minute or two. This happens maybe once or twice an hour. The framerate drops a fair bit every 10 minutes or so, usually still playable. Keep in mind the beta does not make use of dual core processors, and I plan on upgrading before the game comes out. So, that's my view on the technical side of things.
I play a Conquerer, a 2handed weapon / dual weilding class, with shouts to buff team mates around me, and I've really enjoyed it so far. Combat is a lot of fun, pretty much as good as I expected it to be. Skills are pretty decent, although their descriptions and effects, and some combos seem to be just repeats of others.
The first 20 levels of the game is split into 2 parts, mmo daytime quests, and single player "destiny quests" during night time, which progress through what seems to be a pretty decent story so far. This part of the game, up until level 20, serves as the newbie grounds, and the game is free to play during these parts (monthly fee doesn't start until after 20).
The interface to the game isn't quite as good as guild wars or world of warcraft. Usability seems weak, and things aren't very intuitive, but it's not really bad.
I have yet to try any PvP, as I want to twink my guy first. Then I'll try out a few other classes.