The time is ripe for ReWire master and bi-directional audio
This topic has been brought up several times before but I think that now, after the release of Reason 6 and the fusion of Record, the time is ripe for making Reason a ReWire master and adding support for bi-directional audio in ReWire (and also the inclusion of MIDI Out).
These features would enable us to do things that aren't possible today. For instance if someone developed a VST Host that acted as a ReWire slave, and with the inclusion of MIDI Out, you could get a form of plugin support in Reason (i.e. you could sequence that VST Host from Reason and send the audio back into Reason and record it).
Ah well, most of these suggestions are known already.