Most people who’ve heard of CMMI are familiar with what today is actually called CMMI for Development.  The current version is v1.2 and earned the "for development" moniker when it transitioned from v1.1 to v1.2.

Why was "for development" added?  Because, in August 2006 when it was released, CMMI for Acquisition was already on the path to being released (which happened in November 2007), and CMMI for Services was somewhere else in the pipeline.

The three, collectively, are referred-to as constellations.

Here’s how I distinguish the three constellations:

Development = Build stuff.
(Tangible, storable products, made to spec in a life cycle.)

Acquisition = Buy stuff.
(Specify, solicit, select contract, procure, accept, transition to consumer.)

Services = Do stuff.
(Intangible, non-storable, products delivered via a systemic way to deliver the service.)

The Service constellation will be very important for a large number of organizations because so much of what they’re doing would really be better characterized as "providing a service" despite the fact that the service they’re providing is software development.

Why is this important for "Agile" organizations?

Because (and this depends on several other factors), it may be possible to use CMMI for Services to achieve a real CMMI rating that has much less of an immediate, adverse impact on development activities than might be experienced (when not done correctly) with CMMI for Development. 

(This is true of any development activities, agile or otherwise.)

Allow me to be clear, CMMI for Services is not a "cop-out" of CMMI for Development.  Though, CMMI for Services may be more appropriate for some organizations than CMMI for Development (which is why -Services was created), and so this is an option for them, not an option for everyone.

So… what’s next?

CMMI for Services is expected to be officially launched in March 2009 at SEPG 2009.  Appraisals against it will be accepted about 6 months later.

In the meantime, people interested in CMMI for services can start using it under controlled piloting efforts underway with the SEI.  Feel free to contact me for more information on piloting the CMMI for Services.  (I’m helping the SEI with that.)