Microsoft released a consumer preview of Windows 8 a few days ago. Within the first 24 hours the new preview had been downloaded over 1 million times.
When Windows 8 was first announced last year and when the first preview was made available, 500,000 downloads were seen that first night. The 1M in 24 hours seems to be about in line with where it was last year when downloads opened up.
Microsoft expects downloads to treble within the first week. What will be good for Microsoft to see is the press giving the test product a good write up which has happened so far.
Expect to hear more over the coming weeks and months as the release date gets closer. As well as keeping end users happy, Microsoft also needs to keep plenty of developers on board to keep interest in the operating system. Windows will always be a success due to how many boxes it comes pre-installed on around the world, but Microsoft still needs to keep people buying those PCs instead of defecting to another platform.