Indeed now that stored procedures CALL is not binlogged, but instead the invoked substatements are,
the restrictions applied by log-bin-trust-routine-creators=0 are superfluous for procedures.
They still need to apply to functions where function calls are written to the binlog (for example as "DO myfunc(3)").
We rename the variable to log-bin-trust-function-creators but allow the old name until some future version (and issue a warning if old name is used).
Approximative, because it's using our binlogging way (what we call "query"-level) and this is not as good as record-level binlog (5.1) would be. It imposes several
limitations to routines, and has caveats (which I'll document, and for which the server will try to issue errors but that is not always possible).
Reason I don't propagate caller info to the binlog as planned is that on master and slave
users may be different; even with that some caveats would remain.