First, I have to give kudos to the BioWare team. I'd just about given up on MMO's until this came along. A game that's reasonably challenging, with an engaging storyline that didn't dumb down the content so everyone capable of clicking a mouse can hit the "I Win" button.
I've been playing MMO's since 1999 and survived some horrible launches (EQ, DAoC, Anarchy Online), so far this game has been an incredible, amazing experience. I wanted something where I couldn't steamroll content, where crowd control wasn't "optional" but a requirement and where leveling didn't feel like a grind fest just to hit max level.
I know there's various people complaining that the game is too hard and if I had to guess these are the same people that whined to another MMO company that their game was too hard until said company toned down the content to the point where people started to quit. Force people to learn their class and to learn how to use crowd control and interrupts. Those are the things that make this game a challenge and what makes it fun :-)
There is quite a bit of potential for the game. I would like some customization for the UI but I'd love it if BioWare stayed away from the damage meters because too many people develop tunnel vision and that almighty meter is ALL they care about.....it takes more then just good damage to down a boss, you also need coordination and skill. Unfortunately, many players forget this simple fact.