I own Cubase SX and Nuendo2 and of course, I have the sk880 which prides itself with the best internal sequencer in the market (well, not the best, for Genesys has beaten it) and I use both the internal and external existensively. In fact, I almost use all features, and if they added more features, I will use the added features.

I think a nice feature will be if they can have a digital out on the keyboard so one can transfer 8 tracks of 24bit/44.1khz at the same time to the computer.