I just read TFA from Adobe and I understand all. It's not that Adobe is dropping support; they know that Linux upgrade cycles are extremely short compared to Windows / Mac OS X, they will maintain Flash 11.2 basically to fulfill the demands of Debian Stable / RHEL / SLES users, and they will attempt to move everyone in Linux to PPAPI.
I even APPLAUD this move. Linux are always the guys who start the trends, and that will be preserved. The first ones with a 64 bit Flash plugin, the first ones with the next-gen plugin API.
I see Adobe hasn't defined how it's going to distribute the plugin, and that's because nothing but Chrome supports PPAPI. If Firefox doesn't want to support PPAPI, I bet 1,000 internets that Webkit will support it, and every Linux user is going to ditch Firefox and run Konqueror + KWebkitPart, Rekonq, or Midori with PPAPI support, instead.