I've been otherwise very happy with my K10D but it's low light performance has left me wanting better. Apparently ISO 1600 on the K20D is at least as good as ISO 800 on the K10D so one extra stop is gained. Another feature of the K20D that got my attention is the possibility to tailor the AF focus precisely for each lens.
I found a K20D locally for 350 euros and it comes with an extra battery + remote. Only has 3500 actuations so almost pristine. Not a steal but a very good price IMO.
Now I'll have no problem with skipping both the KX and K7D and waiting for whatever is around the corner.
One happy camper fishing for pats in the back