The druid's wildshape is considerably less powerful than a wizard's simple 4th level spell - polymorph. A brown bear comes off second-best to an annis hag, for example. The wizard can cast all his spells in annis form and his magic items don't meld and become inoperative. The annis is stronger, has a better AC, and has reach and rend. If you can be bothered and have time, put bull's strength, fire shield, stoneskin etc. up. So the power of the wildshaping druid is not something to be scared of, nor is it particularly out of the ordinary for 8th+ level characters. You're simply playing to the wildshaping druid's strength - close combat. IIRC, there are plenty of places and plenty of bad guys in RttToEE which don't play to this strength. You can always replace a bad guy or two for "set-piece" battles. Let the druid get cocky that he can tear apart anything he comes across. Then get up in the air. See how effective the druid is against the erinyes ranger (archer-build) you've put in the Fire Temple, for example. The druid can wildshape into what - an eagle? Even a mid-level wizard with fly and displacement up becomes a reasonable contest.
Cheers, Al'Kelhar