I can't speak for end-game class balance as of yet. Errors, and work have kept me from level racing like I usually do. However, through parsing mid-level dungeons between guildies who I've known to be good mmo players for a long time, I've observed that most of the dps classes are right in line with each other. For the most part my DRG will win on a short fight because of burst CD's. However, on a long fight my friends and I would often be 2-3 hundred damage apart on a boss, for overall damage.

The only class so far I have noticed lacking a bit is summoner (of course including the pet dps)