Hi Christian
The Vocal processor is under developement and will be released after the new OS 3.0 Kubuntu.

My main MS OS developer Christain ( same name like you ) will value to add a new plugin engine inside the GIGA LinuxSampler.
This new plugin allow to streaming the Voices in Realtime from some Jack audio Inputs ( from the Microphone MS inputs)
Instead to read the wav sounds file from the Hard disk, the sounds data will be take from the MIC Audio Jack inputs.
With the all ready features of the LinuxSampler we are then able to manage in Realtime how many Voice we like, uncluding also the all midi implementation features available o from the sampler.
I think then that 6 additional voice are enough for the Vocalist section, here one not complete demo MS interface that we use for testing this new plugin: http://www.lionstracs.com/demo/vocalistdemoUI.jpg

About the touchscreen: normally you have to use it of the all others NOT mediastation application, where the all features are not linked by API to the MS keys pannel.
For example Firefox web browser, some complex VST/ASIO that need to editing some function only by the original interface.

Right now we use Linux Debian with KDE 3.5 interface, you can also download for free the OS distribution from here: http://www.64studio.com/
We use the same distribution too, but with added the all MS package and utility.
Really soon, when they are ready, we will porting all the MS OS packages under Kubuntu version for a totally new multimedia 64bit native OS distribution.
cheers