I just don't see what Ambient would have to do with it ???

Updating TaskManager and CPU-Monitor-screenbar to display 2nd CPU useage might be usefull, but apart from that ?

2nd CPU-tasks will need some way to allocate memory from ABox-side and some methods to send/receive messages.

Those tasks wouldn't have any access to other system-resources like GFX-HW or the filesystem. Atleast not in an initial AMP-enabled MorphOS.