In a new announcement at the Building Windows 8 blog, Steven Sinofsky detailed that Windows 8 is getting treatment updates before General Availability, that is October 26th.
According to Sinofsky, the new updates will improve performance, power management and battery efficiency, compatibility and media playback. These new Windows updates are available today for users currently running the RTM version of Windows 8 — BTW the cumulative updates are a total of 180 MB.
There is a gap of 8-12 weeks between the RTM and the retail version of the OS and Microsoft is releasing the updates within that period, instead of waiting and release the first Service Pack. Clearly the software giant is trying to deliver the best possible Windows experience to customers from day one. Considering that the operating system already faces many challenges as with the new UI, users will have to relearn many things, including how to navigate the OS and understand the new application model.
Source Building Windows 8 blog