Response pulled from the Monero Speculation Thread
This is a great idea. One thing I must mention for cost averaging to work correctly one needs to specify a fixed amount of XBT per day not a fixed amount of XMR per day, if one is purchasing XMR with XBT.
Thank you for the recommendation! We (well, that's the queenly we... onemorexmr is the one with the magic computer skills) is currently implementing this change.
Onward and upward!