There is talk that with Technet, a subscriber will get a single key for Windows 8 and that key can be used for unlimited installs, but only 1 activation that becomes tied to that machine and cannot be moved to another machine. This was discussed by Paul Thurrott and Mary Jo Foley in the Windows Weekly Podcast #272 from August 2, 2012.
People shouldn't count on Technet for licensing of their Windows 8 boxes. It sounds like MS is going to really restrict that usage and instead expects people to simply pony up the $40 they are asking.
Well or whatever the "System Builder" costs but yeah.
And uh... ALL windows disks have "unlimited installs" if you don't activate them :/ It really just means "You get one activation with one key". In fact, it sounds like it may in fact be a System Builder version as opposed to the retail versions of Windows 7 you got on Technet.