Microsoft just announced on MSDN/TechNet ( http://msdn.microsoft.com/en-us/library/ms698807(v=vs.100).aspx) that the FIM 2010 Connected Data Source Extensions or XMA/ECMA1 is marked a deprecated feature. This effectively means that any Extensible Management Agents build on this old framework in a near future is not supported and would have to be replaced by a version build on the 'new' ECMA2 framework (http://msdn.microsoft.com/en-us/library/windows/desktop/hh859557(v=vs.100).aspx).
So if you have build a Management Agent on the old framework, you should rewrite it for ECMA2 and if it is one supplied to you by a vendor then you should contact the vendor to see whether or not a newer, supported version is available. And if your vendor does not have a version ready, you maybe need to push them for one.
So, in my opinion, you should actually start this work right now as it probably could take a while to plan, test/build and introduce a new MA (maybe with missing or different features) into your FIM production environment to replace the deprecated XMA's. So there is absolutely no need to wait, take action today.
So far there are no indications of whether the possibility to run ECMA/XMA MA will be removed completely from the product, so we'll have to see what Microsoft decides on in that regard.
Hey, I'm using your Home Directory MA - what should I do?
If you happen to be running my Home Directory Management Agent, you'll notice that this is written in the now deprecated XMA framework. If enough people report that they would like to see an ECMA2 version, I will definitely consider this. Otherwise, it is recommend using my PowerShell MA as a replacement (more on this later)
So again, if you're running XMA's today, take action to get an ECMA2 version in production as soon as possible.