It depends on the babe, actually
Dylan still had four milk feeds per day until about 13mo, then went to three per day. That was more my decision than his; I had returned to work at this point and it was just too much to pump enough milk for two feeds while I was there, so we dropped to just one in the middle of the day. At 16mo we gradually transitioned to soy milk because my pumping output dropped dramatically. We did soy milk during the day for a month or so, then did it in the morning too, so only 1 bf at night. So,
12mo 4x bf/day (day feeds ebm in bottle)
13mo 3x bf/day (day feed ebm in bottle)
16mo 2x bf/day, soy milk during day (slow transition, mixing with ebm)
17mo 1x bf/day bedtime only, soy milk throughout rest of the day.
But that's just one example! FWIW, the World Health Organization recommends staying on a minimum of 4 bfs per day until at least 10mo, but with no hurry to drop bfs at that point. Remember that after 1 year, since milk is no longer the focus of their nutrition, it's also time to make the transition from milk as a *feed* in and of itself to more of a drink. So if you're planning on weaning around that 1 year mark, you could start by bfing only morning and night and offering other milk through the day. Once that's established, you could change one of the other feeds to milk, and once that's established you could drop the last one. Ultimately, MPI or not, the actual process of weaning doesn't change that much, it's just what you're weaning to that changes.
Not sure if you saw this FAQ?
http://babywhispererforums.com/index.php?topic=157385.0 Some information there that you might find helpful