after playing with the unit for a few days I simply LOVE this thing.
In cubase you can add an instrument track, then simply select the Keylab plugin, you can then assign to any output, midi, can change everything including program change, the plugins screen pops up in edit mode and you can use all three, the LIVE, MULTI and SOUNDS tabs.
The more I play with this the more I find how easy it is to use. The 5000 sounds are absolutely KILLER.
I'm using cubase 7.0 on a windows system 64 bit.
I hope that helps clear it up