Make a cross-realm dungeon queue
I always wait 1 hour in the queue for specific dungeons on the server with the highest population. It seems like a big problem for most of the players. I know it is possible to make a cross-realm queue for dungeons to make people feels more comfortable.
My suggestion: make cross-realm dungeon queue, but with restrictions for people from Icecrown with high GS to not ruin the blizzlike atmosphere on other realms. You can just make it depends on gearscore and people with almost bis characters on Icecrown will be queued only with people from Icecrown or with people with same GS from other realms.