I've been on MFP for 10 weeks and have lost a staggering 19lb 
Never in my wildest dreams did I think I would average almost 2lb per week for 10 weeks. I've had a look back over my diary for the 10 weeks.... There have been super high days (ie 800+ over my target cals) and lower days where I have done exercise and not eaten all my exercise cals. Overall, I reckon I'm about 600 cals over for the 10 weeks - about 9 cals over per day. I guess this is proof that MFP really does work.
So, where next.... Well, I still have 22lb to lose to get to my goal of 9st (am 10st8 today, and started at 11st 13). I'd love to average 1.5lb per week for the next 10 weeks - that would mean losing another 15lb by the end of August getting me to 9st 7.
So, my mini-goals are:
10st 2 - my pre DC1 weight
9st 7 - my target end of August weight
I suspect I'll reconsider my 'end' goal when I get to 9st7.... I might be happy at that weight, or I might want to continue to 9st, or perhaps even 8st7 although I suspect that's highly unlikely! (I'm 5ft2 in case you're wondering!).
The more I can lose when I'm breastfeeding the better, as this will diet will be much more difficult when I don't have my 'bonus' 500 cals per day.
Well done to everyone else with good results, and for those who are struggling, or have had disappointing weeks here is a gentle kick up the arse nudge to refocus 