From an aesthetic point of view, sure it's pretty and clean, but from a usability viewpoint, it could be better.

1. Player health is in top corner. The action is in the middle of the screen, it's probable the player will have trouble keeping track of his status like mana or health unless they have a mod like power auras to notify them. Move the player frame nearer to your character.
2. Raid frames are spread out across the screen. To move from someone on the left of the raid frames to the right requires a large movement of the mouse, the raid frames should ideally be bunched up to minimize movement, A grid like format is best for that.
3. Recount constantly displayed. Unless they are an officer, it should be hidden in combat, otherwise it's just a distraction.

The goal is to reduce hand and eye movement as much as possible saving your eyes from straining, your hand from moving too much, and your fellow players from dying because it took you .7secs to move your mouse to their frame instead of .4secs.