Actually it does make some sense if you stop and think about it. The vast majority of game console buyers don't give a crap about BluRay playback. Yet, all who wanted a PS3 needed to pay for that too, and pay quite a bit extra compared to other available machines.
So how do you offer what many of the consumers want (a cheap PS3 for games only) yet hope to recuperate the losses you will take on selling them (since a PS3 needs BluRay).
Disable the BluRay movie playback and offer it for unlocking at a price. In a couple of years, when BluRay disks will be much more common, it will make more sense to unlock it than to buy a new Blu-Ray player.
Also, manufacturing prices have come down more than people think, a PS3 "slim" (even though it will not be slim) will cost less to produce/store/ship than the current PS3, thus the losses would not be large on such a no-BD movie player PS3.
