I'm not sure I follow, Bitcoins are mined at a rate of one block every 10 mins (on average). The difficulty setting adjusts based on how much processing power is thrown at the problem. Supply is constant.
It is my understanding (but I could be mistaken, there is a lot of FUD around BTC) that someone could in theory mine 500 hashes in a ten minute window then 'retire' having boosted the mining rate. This would not only net them a lot of bitcoins immediately but also restrict others supply of bitcoins.
Supply is roughly constant given a slowly increasing mining pool, supply isn't shock resistant.