If you are using windows 8 developer preview please make note of this date; March 11, 2012. Windows 8 Developer Preview Will Expire on March 11, 2012 for those got an early chance to use fully fledged windows 8 platform.If you still not downloaded windows 8 developer preview do it from below link.
All the developers will only get half an year to play with the Windows 8 Developer Preview. Microsoft is expected to bring the beta and release candidate version on mid of 2012 and finally the RTM version for final build may be end of 2012.
I hope the developers will get an early access to new beta version of windows 8 before the expiry date of Windows 8 Developer Preview ends.