I can see the need for a Bug Fix update for AmigaOS 3.9 and possibly an updated TCP/IP stack esp. for LAN/ADSL users. But other than that, I doubt may 68K users would benefit from other features of OS4.
Hyperion have spent a lot of time and effort on OS4, its time Amiga users moved on to new hardware and a new OS4 for the 21st Century. I don`t want 68k stuff to continue to hold us back any longer.