Given that I did away with my linux desktop system recently, I very well might buy MP2 when it comes out.
But the worry is, I may switch back to linux once the Windows 8 preview expires. If that happens, I'll have to leave MP2 behind and switch back to Synergy. I would love to be able to use MP with linux. I'd even take Synergy server support tacked on so that the linux box could run Synergy Client to connect to multiplicity.
Acoustic Bridge seems to be a great idea, and would replace one of the cables I have going between my computers right now...