One of the stranger ideas that came out of BarCampRDU this year was that we might do an iBatis plugin for Grails. Such that GORM could then run on-top of iBatis or perhaps you would tweak iBatis to run a faux-GORM in Grails context.
That seems like an exceptionally hard plugin to write. I think I might need some convincing before I even took a serious look at something like that. It is at least technically possible since GORM itself is a plugin. But, that doesn't mean there isn't an iBatis guru out there that would love to learn how to do iBatis + Grails for the folks that needed that.
Anybody out there interested?