New
#11
Cause before then the real final RTM will be available with ability to purchase legal key. Activating one of these RTM builds that are currently available with a legal key will cause it to never expire. Also, it's a simple matter to upgrade install from current RTM build to the real thing. Upgrade installs with W7 work better than with previous OS's, ime, (at least going from W7 to another build of W7), so conventional wisdom about clean installs may not be so applicable. However, each to their own on that.
Regarding the other post re security issues & possible malware in leaked builds etc., thank you for pointing that out. Didn't really occur to me cause I feel pretty confident in my ability to detect the presence of malware, so that is not a big concern to me. But obviously, each person should do whatever they are comfortable with wrt security concerns.