The informations stated in an earlier update are still valid. No big breakthroughs in the last week (but none are planned, though ;) ).
The Exec Kernel is running in a Simulator (parallel to the normal system). In this time it is ported to the hardware platform.
The rest of the components is in different states of finishing. Some are finished but are waiting for the final converting onto the new kernel (this means just only a recompilation of it).

This is a hint for those who want to start with developing for OS4: Develop for 68k. The sources will be fixed with minor changes to OS4 (it means only one or two lines are added to the sourcecode). You can use the normal Exec API. We will release a beta version for developers that will document the new functions (about 20). It should be a change to PPC at least.