This is a good move on Sony's part. There are three types of modders out there; those who mod to play imports, those who mod to play bootlegs, and those who mod to play imports but end up playing bootlegs just because they can. This eliminates two of those groups, and will cut down on the demand for mod chips. Lack of demand will result in higher prices for mod chips. Higher prices for mod chips will result in less people modding just to play bootlegs. It won't eliminate all of us pirates, but it will curb the number somewhat.
If they were *REALLY* smart, they'd come up with a way to play homebrew software without a mod chip. Even smarter, sell software to burn homebrew software on a PC that puts some sort of requried code on the disc to allow it to play. The homebrew disc would then be copyable in any other program, but in order to make that first copy, you need their program.