No, getmemorypool has nothing to do with setworkaux, coinbases, or merged mining. It's a JSON-RPC command that was merged with even less review than coinbaser, and is only used by a single pool.
Huh? getmemorypool discussion is/was here: https://bitcointalk.org/index.php?topic=39088.0
I'll just note that I'm damned if I do pull stuff that has some discussion here (and no objections raised), but damned if I don't pull stuff that first had no discussion, and then had a little discussion with some dissent.