It's hard isn't it? I ran into the same problem, I really really want a Worgen tank but that leaves only two options.
Warrior tanks are hurrrting right now. We'll see how they do in a few months.
Why tank? Cuz if I'm gonna do impressive transformations into some powerful cursed mythical beast, I don't want to be no weenie caster.
Anyway I used to be like you. The first thing I traded out was one of the elementals for a hunter. I don't remember why, other than I thought they'd be quick to level and I was hating those long graveyard runs through Utgarde Keep and wanted fast feet.
Next I decided to raise a mixed team to replace the other shamans (not permanently, just to try something different) so I went with DK tank, BM hunter (somehow I thought this meant the pet would do a significant amount of damage), Warlock (for the summoning and healthstone and soulstone and pet DPS), druid (originally healer then boomkin but then IWT/Click to move made it more fun to play a feral) and priest (originally shadow but in those days druids were terrible group healers, so I made the priest holy)

My final group is the swiss army knife restless group. Pally tank (Crusader aura), Hunter (Aspect of the Pack), Shaman (Heroism), Mage (Portals), Priest (easy sauce macro heals as holy. Probably easier as Disc)

Now I look at it and see that Mages are going to get their version of Heroism at 80. Maybe I too will bump the shaman and make a lock for summons instead. 'cuz between the 5 of them, i've got 4 different flight speeds.