How many hashes create one Bitcoin?
These charts show the approximate network hash rate on the left axis:
  http://bitcoin.sipa.be/

We know the network adjusts for 25 new bitcoins per 10 minutes.

Together this provides enough info to give an approximate answer to your question:

hashes per bitcoin 
= (network hash rate) / (25 BTC per 10 minutes)
= (180 * Th / s) / (25 * BTC / (600 * s) )
= 180 * 600 / 25 * Th / s / BTC * s
= 2,700 Th / BTC
= 2,700,000,000,000,000 h/BTC