I am getting in touch with Cakewalk about this, as we’d certainly like to get sidechaining working in VST. The VST spec doesn’t directly support sidechain like RTAS, Audio Units, etc. but VST plug-ins have used workarounds, so we’ll plan to get something working with Sonar at least.
yeah, that would be great! Consider doing it in a way that is compatible with Live as well, as audio can be routed to extra plugin inputs quite easily.