Everyone is talking about FIC Neo1973 (even Dodji who does not like such toys usually :) ). This phone looks nice, the software platform looks nice and I think I would use it more than my Nokia 770, ... if only it had WiFi.
If I change my simple phone to a nice smartphone it will be one with both GSM and WiFi, and the ability to have clever algorithm to decide if using GSM or SIP over WiFi for a given call (use GSM for cellphones, use SIP over WiFi when WiFi is available and the target is in the free destinations list, ...).
An old interview says that next model will have WiFi. I think I'll wait for that one :-)