[Meads]

It's not even been comfirmed that there is a rewrite of the playback engine, has it?
However, of course I'm sceptical given Avid's catastrophic track record with major changes. Anyone remember those random fullscale noise blasts?
PT has been a trainwreck ever since the big rewrite couple years back. It was not until a year ago or two that they finally managed to reach an acceptable level of stability again.
So, yeah, I bet a new playback engine will just be another Pandora's box for the first couple iterations. I'd happily be proven wrong.