The Lenovo key will become invalidated as soon as MS publishes an update on Windows Update to disable it (note that you would then have to download the update and install it to have your PC to be affected). We will never know exactly when that will happen unless MS makes a press release and tells us about it. The best guess, and in all probability, would be by the time Service Pack 1 is made available for Win7... We can expect new keys around the time OEM PC's (e.g. Desktops and Laptops) begin to ship with Windows 7 preinstalled.
This discussion leads to nothing.....we already have got that a lot. These leaked keys you may check with PIDX checker, they are no SLP_OEM keys.....closed!