My understanding of it is the second tuner does nothing until a firmware update comes out to make use of it with the PVR properly. That way you can record one channel, and watch another on another sat.
The two tuners are both supposed to be DVB-S2.
Edit:
Did some further research by popping open my VS9000, V2.
The first, built-on tuner is a Conexant CX24118A DVB-
S2 tuner paired with a Conexant CX24116 DVB-
S2 demodulator (
http://www.conexant.com/servlets/DownloadServlet/PBR-200920-002.pdf?docid=921&revid=2).
The second tuner can be removed pretty easily, being an add-on board. The Demodulator is an Intel WJCE6313 DVB-S tuner along with a ZarLink ZL10037 Tuner. The ZL10037 datasheet (
http://www.datasheetarchive.com/pdf-datasheets/Datasheets-41/DSA-802459.pdf) has it's applications as DVB-S Free-to-Air Satellite receiver systems as well as 8PSK systems.
That should put this to rest. It DOES do DVB-S2, at least on the primary tuner.
Edit, again: The factory software has no settings for S2, but a somewhat recent alt-ware file does allow you to set a particular transponder to S2. However, after trying a couple of S2 transponders on AMC3 that are listed on Lyngsat and another I know of on another sat, I get nothing.
So, hardware is capable, software is a big ???.