Yes, webOS 2.0 will be coming to older webOS devices, but Pixi won't get flash
Current Pre, Pixi, and Plus variant owners: relax, you’re getting webOS 2.0 too. Same “coming months” line as before, though hopefully we won’t have the same debacle that we had with the super-long webOS 1.4.5 roll-out. We now return you to your regularly scheduled programming.
Speaking of updates, @webosinternals noticed that "the fine print" on HP's massive webOS 2.0 / Palm Pre 2 Press release makes it clear that the Pixi and Pixi Plus are not compatible with Flash:
(6) The Adobe Flash Player 10.1 Beta is compatible only with Palm Pre devices; not compatible with Pixi or Pixi Plus.
That's a situation we'd like to see fixed but, deep down, don't think will be.