This week has been full of speculations. Windows 8 RTM is expected to be complied this month and rumors are prevaling that Windows 8 RTM could be shipped with build number 8600.
But rumors are also swirling around that Windows 8 RTM could be shipped with build 8800 or build 8888?
The second one i.e. build 8888 seems more promising to me because Microsoft seem to like the number 8 at the moment.
Windows 8 has got the digit "8" and build 8888 is full of 8s.
Build 8888 will be 1288th build since Windows 7 final build which was build 7600, also includes 8.
Still these are only rumors and there isn't any official confirmation from Microsoft yet.