Interestingly MS have left all the voice work for 3rd parties to deal with, although the Vista voices are a little better than their predecessors. So you aren't going to get any voices from MS but there are, I'm sure, plenty of other vendors releasing voices.
There are some potential pitfalls with using PN Media/Music manager with a custom DMS.
In my tests with the new [not yet released] tools, I couldn't get Music Manager 2.30 or Media Manager 3.92 to actually recognise the DMS at all.
However, there were no such problems with PhatHack Media Manager - although I have yet to do any work with Free Space calculations, which should be relatively trivial.
At this point I'm hoping someone can jump in and tell you which version of PN MM will actually work with a custom DMS, as I'm not concerning myself with it seeing as I'm getting to the point where PhatHack MM will soon be writing the DMS content.
By the way, looking forward to the new software. I know how hard you have to work to accomplish something that seems absolutely trivial to most people...
Well, when I've been writing it's certainly seems relatively trivial
The hardest part, as strange as it may seem, has been building the media player.
the parts that I would have considered to be less trivial [Ripping from CDs and transcoding the audio files] were done really quickly!
Anyway, I look forward to actually having my DMS managed by something that I know can be fixed - as I'm sure everyone else does!
It's just a shame the audio libraries I used aren't x64 compliant yet - everything else definately is, as I've written it to be!