I felt this was important enough to have its own thread.
Someone on Gearslutz made reference to this, and I just watched the playback of the Q&A session with Tom Graham, Rich Holmes, and Tony Carridi.
To me there is no vagueness about this at all.
Tony makes it very clear that this CPTK and PT10 upgrade offer to HD11 is a
one time deal. You won't be able to upgrade from HD11 to HD12, or HD13, or whatever, and continue getting the full software features without buying an HD system. He states that going forward, if you want the full features, you will need to buy an HD system.
You can watch it here, starting at about 10:25 in the video:
http://www.protoolshdx.de/Dokumente/Home.html
My interpretation of this is that this is meant to placate CPTK owners during this transition of the CPTK being discontinued.
So this might be a sensible purchase if you plan on staying with PT11 for a few years, but not if you tend to upgrade to each new version.
I just wanted to point that out so people know what they're getting and not getting down the road.
If anyone from Avid would like to elaborate or correct this, feel free.