Hopefully it works so that as each week passes, you will gain more rating than the week before, so that by the end of the season even if you just started playing that week you would have the full effects of the inflation.
I have a horrible feeling that you need to play every week to get the full benefits of the inflation though.
I hope it inflates the whole ladder not just your arena team so that if you start playing the last weeks you can farm those team that have been feeding of the inflation and gain their MMR. But it wouldn't surprise me if it was a "Blizzard system" so that you can't take other peoples inflated MMR or something dumb like that, you have 2350 MMR and 30 of those are inflated so the system threats you like you beat a 2320 team and gave you MMR according to that.
Ohwell, there's no details out maybe it's a great system just none knows how it works.