Does anyone know what BC's to set in ICEM 5.1 to successfully read into Fluent6? I can write the mesh file and select the appropriate wall/inlet/outlet conditions.. But I believe my problem comes with setting the interior and fluid domains (which GAMBIT previously did for me). Or is there another trick involved with stting the mesh as structured/unstructured?

ICEM tutorials on this seem to be non-existent

You don't need to set any BCs in ICEM CFD. For Fluent6 you'll need unstructured format mesh - so tets/prisms or unstructured hexas. You'll probably want to write the Fluent mesh as ASCII as well. The families/parts from ICEM CFD should come through as regions/zones in Fluent - both surfaces and volume regions. If you haven't retrieved the Service Packs (1 and 2) for ICEM 5.1 - you'll want to do that as well. If you continue to have problems, contact your technical support provider.