to iphone 4 or to iphone 4S???

here's the thing - my contract runs out at the end of november and i need a new phone.

now i have been really disappointed with my nokia n97 - bad from the start :(

i have looked and played with a few droid phones but i am keen for an iphone - yes i think i have become a mac geek.

so i am wanting oppions from everyone - do iphone 4 or wait and iphone 4s it???