For the Q Body: http://www.pentax.jp/english/support/digital/q_s.html
For the "01" Prime and "02" Standard Zoom: http://www.pentax.jp/english/support/digital/q_lens_s.html
Btw, "Improved stability for general performance" = Debug(ged) in One Word!
And, it is for the first time the firmware of a Pentax lens can be upgraded by the user oneself, just like that what can be done for the lenses of all other ILDC systems.
Update (11-3): New SilkyPix Software is also available for the Pentax Q, version 3.0.0.3:-
http://www.pentax.jp/english/support/download_digital.html#soft