Charley,
You want proprietary Yamaha created Style files (not MIDI files). You can edit your own style files and share them, or downloaded created styles, but you can't exchange Yamaha Created Style files, as they are proprietary (this is according to Yamaha). You should not exchange PSR9000, PSR8000, Tyros, etc. Yamaha created style files. I would imagine that Yamaha's thinking is that you might upgrade to a PSR2100 to get the new styles. If you can download them for free, that incentive anyways, is taken away. I have problems with this marketing technique, as well. Why buy a whole new board; with new speakers, new amplifier, new keybed, new o/s, just to get new styles. The PSR2100 has new styles, more storage, and USB. This should be an upgrade to the PSR2000 not a whole new keyboard.
Starkeeper