Perhaps sooner, since Flash support is a plug-in to the browser. This could be done as an update from Application Manager with the correct files.

OP posted. "Application Manager doesn't list the Flash plug-in as one of the things it can control." -- was this in red pill mode? I'm sure this can be patched somehow. App manager installs stuff as root (I think) and has direct access to the filesystem, so I fail to understand how this cannot be patched.

Adobe may not list a .deb file available, but this should be raised as a bug in Maemo so that the OS developers are aware of the problem and can assign the fix to the appropriate member of the team.