Its difficult to say if you will run into problems or not. I dont know the ratio of people having problems against those who dont, but there is a very substantial number of people having problems with this game.
Personally, i dont suffer from CTD's (only ever had 1), but there are other problems like freezes, sound problems of all kinds (from machinegunfire to no sound at all), etc.
If you are a TW fan, i would suggest to get the game. Then install it and hope for the best basically. If you are not a TW fan, my suggestion would be to wait until a few more patches have been released (seeing that you are on this forum though, i take it for granted that you are a TW fan)
Even if you dont run into any hardware related problems whatsoever, there will be plenty of "problems" ingame. Once the initial "whoa" feeling has subsided, you'll pick them up.
There is a game content patch in the making, scheduled for release next week or the one after that, hopefully that will take care of a number of these issues
Regarding patching in general, you have to connect to Steam in order to authenticate your game, so any patch available for the game will install automatically from there.