A couple of high level observations:

1. As Yury notes, more clearly separating coroutines and generators is the
intent of the PEP. The computer could clearly cope with them being the same
class, but humans tended to get confused. We were still blurring that line
too much in the initial implementation, this patch aims to fix that by
*really* introducing a separate class for native coroutines.

2. Missing integrations in other modules that are likely to result in
misbehaviour in user code (such as the inspect module not accounting for
the new ABCs) are good candidates for filing as behaviour bugs - finding
that kind of gap in PEP implementations is one of the benefits of the beta
period.

3. Integrating nicely with both asyncio and Tornado is a good pragmatic
design goal to avoid making too many asyncio specific assumptions