Well...dvd burners were for retail sale, plus mod chips were flying around everywhere. I dont see any blu ray burners for sale so far, not to say they wont be released eventually, but I think Sony will be pretty safe for a while...not to mention the cost of a blu ray disc, 1 blank DVD used to cost like $10, for 4.5gb space, imagine a 50gb disc...you may as well buy the original game, at least then you can re sell it and get your money back. Plus, blu ray is quite new, PS3 is virtually the only machine that can play them, so until they become a bit more mainstream, we have little purpose for burning blu ray discs. And back to the mod chip thing, a mod chip for ps2 cost like $50 here, and if it stuffed the machine up, just pay another $400 for a new one, whereas given how expensive the PS3 will be, its not worth forking out over $1000 for another one in case you stuff one up.
Plus add in PS3's previously mentioned activation thing, even if you burnt a game, you cant play it. But of course someone will figure how to hack the hdd and bypass the activation thing...gotta love and hate hackers.