I'm presenting a webinar tomorrow at 11am Boston time (1600 hrs GMT) entitled IMS - What Does an Application Developer Need to Know?
Today there are some push-to-talk services based on IMS, but mobile voice telephony continues to be based on circuit switching, because operators are interested in new services, not in changing things that already work. As it's early days for IMS, there are only a few actual IMS services in use or proposed today, but that number will grow. At a minimum, every application provider needs a clear roadmap of how their application(s) will migrate to, and leverage, IMS infrastructure.
Surprisingly, despite all the IMS standards gobbledygook, only a few parts of the typical application platform have to change in order to convert an Intelligent Network application into an IMS application.
If this sounds interesting or relevant, listen in tomorrow. Alternately, a few days after the webinar we will post the slide deck by itself and with a recording of my "insights," such as they are, in the NMS webinar archives.