Ok... Here is pretty credible info from my source who is currently in Geneva.

It in 98% mirrors info provided here by Whoopsy.

991.2 GT3 will be available as manual and PDK. Manual version will be basically 911R mechanical wise with GT3 tuned suspension and new 991.2 GT3 look. PDK version will be same engine combined with PDK and e-diff. 

Accelerstion wise manual will be as fast as 911R while PDK will be at least as fast as 991.1 GT3 RS with 320km/h top speed.

Price.... Belive it or not idea is the same price for both manual and PDK. Manual will be positioned as purists version and PDK as non-purists version. PDK will be faster, both acceleration and track time wise.

When... After the production of 991.1 GT3 RS and 911R ends. So, intro could be this year, but deliveries definitely in first half of 2017.

Btw, 991.2 GTS will be definitely introduced in late summer 2016.