I know there is a lot of whining here about slow Linux support but waiting for a more polished support package isn't a bad idea. Better to merge in after 3.3 than to have buggy support.
We are trying to get all the invasive changes (multiple rings, memory management etc..) pushed out in time for the merge window. Hopefully the remaining changes for GCN will be specific to new HW, but I don't think we have discussed getting them in post-merge yet.
BTW from this point on I'm probably going to switch from talking about GCN to talking about SI (the first generation of GCN parts), partly because it's one less letter (I'm big into efficiency) and partly because that's the terminology we use internally and I'm getting tired of typing SI, backpacing over it and typing GCN instead.