Ok. Few obvious questions cause your answer is 'in shedure and rocking' and I have learned to suspect anyone giving those:
A) Does it boot up to WorkBenck on PPC only .. (like CSPPC)?
B) Is that mentinoed 68k Intergation finished?
C) Can OS4 be demoed on Cebit?
D) ... running on Amigaone?
E) ... and using well known 68k apps?
I could comment about the worst part of development.. It's when during debugging you suddenly realize that all parts don't fit together as earlier was expected and some major parts of system goes to total rewriting. Are you surely pass that point that you know it'll all fits together and will work as expected?