I got a chance to wade through the OMTP's new IMS handset requirements document in full, on a flight yesterday. There's some good stuff - and some less good stuff in there.
Best of all is that it wants to make handset applications "bearer aware". I've been banging on about this for as long as I can remember. The notion that advanced handset apps on highly-intelligent devices should be ignorant of what network is being used as transport is ludicrous.
I've argued passionately & at length about why applications should behave differently over cellular and over WiFi, for example, because of different bandwidths, latencies, contexts, ownership, cost, security and so on.
I know that some handset ecosystem participants (eg Symbian) are already up-to-speed on this, and that some operators (eg BT) have also been ahead of the curve. So it's nice to see OMTP spell all this out in black and white as a standard requirement:
"IMS-1160 The UE MUST provide an API to allow an application to request the list of all available radio access technologies supported by the UE (e.g. WiFi, EDGE, UMTS, GPRS, etc)"
"IMS-1180 The UE MUST offer an API to allow an application to choose the bearer (from the list provided in IMS-1160) for a media connection subject to Bearer Policy."
I've given a lot of thought to the possible use cases of this type of capability, and it should significantly improve user experience.
(Incidentally - the "less good" stuff in the document? How much time & money is going to be wasted on implementing & testing the useless PoC capabilities of future phones? Why couldn't the OMTP have just killed that stone dead? Also... no mention of how to deal with multitasking-capable phones)