The woes of playing a DPS; there are a ton. You have to be ready to wait a little while if you want a group, though usually it only takes me like 10 minutes.
Really, if you have a healer, you're golden though. If you get one via shout, or have one as a friend, you won't have to wait at all. Even as a tank, it can still take a very long time to find a group, because there are still almost as many of them as there are DPS. People like playing tanks in this game apparently.
in phase 2 and 3 of the beta i had no problem using the duty finder to do the dungeons
phase 4 was a different story, the only way i was able to even get into the dungeon was by inviting people to my party till i had it filled and it would finally let me in (i had the duty finder on for more than an hour at one point)