No time frame at all. The security driver does not work with Win 8 and the O/S at this time is to unstable to begin coding for its support.
This is a quote from de.bug on the O/S
Originally Posted by de.bug
I know Windows 8 is going on sale around the Oct 26th. A word of caution, if you want to continue using the cheats do not run out and upgrade to Windows 8. The BF3 and BC2 cheat will not work with it due to the security driver. I don't have an ETA on when it will be supported. Once it is a supported O/S it will be listed as such on the cheats sales pages.
I would suggest (before upgrading to it) you read some of the reviews that have been done, most are not good. I know I don't want my PC to imitate the looks of my tablet and phone.
Anyway I know many will want to try it out just don't come in here yelling at me the cheats don't work because I've already said numerous times it won't and I don't know when they will. If you want to try it I would suggest doing it on a non gaming PC or look into dual booting.