I'd buy a Tyros Pro but I'd bet heavily that it won't be happening at all. Even if it did suddenly appear I'd be concerned about what level of support it would have after the 9000 Pro's lack thereof.

Yamaha's recent division of it's pro-synth and PKB (home-portable) keyboard departments only added further levels of seperation between the areas that would be responsible for a Tyros Pro. I found this out first-hand recently when I bought the PLG150-AP piano expansion card for my 9000 Pro and found it had no voice data or application data for using it in the 9000 Pro, which is under the PKB's area. PLG cards are part of the synth department and it only has voice data for the keyboards supported by the synth department (namely the Motif, C-series and S-series synths).

Also I've had private emails from Yamaha reps who've referred to the 9000 Pro as a "failed experiment". That says it all.