Honestly, I've been playing Rift since Closed Beta 1, and while there are quite a few things that can be done to help the overall gameplay experiance, I believe there is one thing that could make it MUCH better, quite easily; In-Game voice.

One of the most irritating things in this game is queing for a dungeon/warfront, and having to take 10 minutes to type out an explanation for fight mechanics, strategies, etc. This could all be solved by introducing an in-game voice system. Make it to where players don't need an outside program like Ventrilo or Teamspeak to be able to communicate effectively. I cannot even begin to emphasize how great it would be to jump into a dungeon, and have the leader take 4 seconds to explain the fight, or call out a command in the middle of a fight to save a group from wiping. In warfronts, this would easily solve a lot of the problems about PuG vs Pre-mades. You have one person calling out targets, and the raid is able to focus fire, instead of everyone targeting different players, and nothing being killed.

Another thing I would suggest, is a target assist window. Have the raid leader/group leader have the ability to assign one person in the group as a DPS assist target, so that whatever that person targets, the rest of the group can see and target easily. As it is now, a player pretty much has to stay targeted on the tank to make sure they're on the right mob. Target assists would make following targets a helluva lot easier.

Two simple suggestion tht could make a good game great. Just my two cents. Troll as you will, but hopefully enough people can get behind this to actually see it implemented.