There's been quite a lot of renewed talk about IMS-capable handsets recently. It's still early days, and most industry participants still only expect to see large-scale mobile IMS service launches in 2009 and onwards, but there's definitely a sense of movement. Some of the problems I identified last year appear to have been fixed.
A thought occurred to me, however. There is also now a definite move towards the sale of open, 'vanilla' handsets, both through established non-operator channels like Expansys and Nokia's own stores, but also catalysed by shifts like Verizon's new openness policy.
How will these vanilla devices be configured to access a given operator's IMS? What needs to be provisioned, downloaded, set up? Can this be automated? Can there be a 'native IMS client' which will automatically register work with anyone's IMS infrastructure, or is this too much of an interoperability headache? Presumably, this would only work with the core set of IMS applications (IM, presence, videoshare, PoC etc) as it presumably wouldn't be possible to download an arbitrary 'cool, differentiated, operator IMS app' to an arbitrary IMS handset framework.
I guess a similar situation will occur when roaming with an operator-provided IMS phone onto a foreign (non-affiliated) operator's network.
Sorry, I don't have any answers for this one at present, but it's something I'll see if I can check up on soon.