Heh... nothing much different there than we've had with their last few OS launches.
What I'm waiting to see is if OEMs will be offering both win7 and win8 on new machines, or possibly even continuing to ship all of their desktops with win7 + free win8 upgrade even once win8 is officially launched.
IIRC, once Vista hit the street, XP was no longer available from the cookie cutter big box OEM machines, I'm not even sure if companies like Dell allowed you to select between XP or Vista when "building" an order online.
I'm going to put my tin foil hat on here and suggest that folks might want to read the fine print on these "upgrades" very carefully. I wouldn't put it past MS to lock the win7 COA key to win8 when/if an upgrade is applied, and not allow the user to revert back even if they attempt a fresh reload. (It'd essentially be the same as if the machine was originally purchased with win8 on it).
I have no facts to base this on, just feels to me like the kind of thing they might do in order to press forward with their attempt to get folks to adopt/adapt to the metro interface at all costs.