magic items don't work when you use wild shape.
in the world of min-maxing, and powerful magic items: this has serious implications.
in NWN2, for example, druids are considered seriously underpowered.
in PnP, they are considered one of the most brokenly-powerful class around.
the major difference is the wild shapes and spell lists that are allowed.
it all, of course, depends on how a druids abilities are implemented.
generally speaking, druids are poorer healers and don't have as many combat buffs as clerics.
their damage & CC magic is roughly equivalent to a cleric.
they probably won't have animal companions, but of course clerics don't really have turning or domains either.