Most likely made like this to combat flashed HDD but nothing stopping you opening it up extracting fw and flashing to simular branded hdd
Like a PC it can easily be removed, only time will tell what needs to be done to get a larger hard drive in there. It's a shame users cant officially add a 2TB sata hard drive inside the console, 500gb is nothing these days, neither is the 320gb max you can get in an un-modded 360.
yeah my 1TB hdd with about 20 gamesfrom steam gets reduced to about 500gb as most games these days are 7GB plus and there getting bigger in texture size each year
If you look at the size of PS3 games now, some 30GB+ (although i personally think they just didn't bother compressing stuff in a lot of games) that is certainly going to be more the size we are looking at next gen!