Don't worry your pretty little head -- you can still swap out or upgrade your hard drive on the upcoming PS3 Slim.
Some of you expressed concern that the upgrade and new form factor would prevent you from swapping out the factory drive for another. Seriously, Twitter lit up. I couldn't see this being a bigger concern than the whole lack of backwards PS2 compatibility, but I guess it was for some.
A Sony representative tells Destructoid that you can snap into a Slim and upgrade your hard disk. They encourage this, they say. The PS3 Slim still uses the 2.5” Serial ATA that its predecessor does, and Sony says you need only to remove a couple of screws to perform the operation.
With the "Install Other OS" option removed, you'd only need to do this for a size upgrade. Still, now you know it can be done.