PEP 492: Note API changes due to beta feedback

pep-0492.txt

@@ -40,6 +40,20 @@ programming, as many other languages have adopted, or are planning to
 adopt, similar features: [2]_, [5]_, [6]_, [7]_, [8]_, [10]_.
 
 
+API Design and Implementation Note
+==================================
+
+Feedback on the initial beta release of Python 3.5 resulted in a redesign
+of the object model supporting this PEP to more clearly separate native
+coroutines from generators - rather than being a new kind of generator,
+native coroutines are now their own completely distinct type (implemented
+in [17]_).
+
+This change was implemented based primarily due to problems encountered
+attempting to integrate support for native coroutines into the Tornado web
+server (reported in [18]_).
+
+
 Rationale and Goals
 ===================
 
@@ -1451,6 +1465,9 @@ References
 
 .. [16] https://github.com/python/asyncio/issues/233
 
+.. [17] https://hg.python.org/cpython/rev/7a0a1a4ac639
+
+.. [18] http://bugs.python.org/issue24400
 
 Acknowledgments
 ===============