New glyph coming for mages in 3.3:

Glyph of Eternal Water makes the Water Elemental permanent, but removes its Freeze ability.

The glyph will also make the water ele's Waterbolt only cost 1% base mana (currently at 5%).

Presumably, if the pet is permanent, if should be able to be buffed as well.

This could make for some interesting mage multibox teams...

Cheers,
S.