Oh i'd love to have that. Being able to free up CPU from VSTs would give me more overhead for playback, which translates into more open creativity.
Many times i just needed a "one-shot" sound from a VST (usually as a transition or bridge riff), but that means i would have to load it and keep it "in queue" even though i only need one note from it. Even tho it might cost me file size (for the sample data), i'd rather have more portability and less clutter in my VST list.
Perhaps if there were a dialog to "Record From" a VSTi, and then an input for the note or notes you want to play (perhaps use a mini-pattern editor with one or two columns). But then again, i'm not coding the thing!