Of course the PS world went hopping mad (mad in a good way) over the option to swap your hard drive - first the manual, then the real deal. Now, word from the official PS forums says that the swap won't void your warranty, but the guys over at NeoGAF have gotten hung up over trying to translate the Japanese manual's warranty warnings. Or, in this case, the Japanese PlayStation support webpage.
For a moment ddk_ps3 thought a line on the support page read, very crudely translated, "Q:Can we swap out the HDD? A: Yeah, u can use any SATA 2.5 inch one but you void the warranty when you swap it." Engrish bites hard in the tailpipe.
But that's not the case. Crude translations are, after all, "Lost in Translation." After a very extensive discussion in the forums, comparing Babelfish Google translations, and a call to PlayStation support, this is what they've got now (and we quote):
If u swap it and it stops working during the warranty period we (Sony) can't support that. If u use the original HDD and it still doesn't work and the drive you tried to swap in didn't break the PS3 we will honor the warranty.
In other words, and to paraphrase ddk_ps3's post, Sony can't be expected to honor the warranty of a PS3 bricked or plagued (and we quote again) "by a crap HDD from a different company." Seems much like Microsoft support asking if you've used a Nyko Intercooler in your 360. In any case, one comment in the forum noted that "the chance of a new HDD actually physically damaging your hardware, PC, PS3, or whatever, is slim." And finally, this may apply to Sony Japan. No specific word yet on SCEA-specific warranty policies.
If anything, the warning is there for legal convenience (and the suggestion in NeoGAF is to swap the old HDD back into the PS3 if you wanna get it repaired under warranty). And as Gino D. pointed out correctly, if the manual teaches you how to swap the HDD out, then, Sony can't hold that against PS3 users. Still, however slim the chances seem to be, no one would really want to risk it unless they were sure there was a safety net or fallback. Simply put: we can't confirm anything 100% until a warranty case actually happens.
The best thing Sony can do is to at least stay on top of the situation, noting which SATA HDDs conflicts with the PS3 (if it even does so in the first place) without holding it against the PS3 owner. Or come up with a list of known reliable SATA HDDs. It's early days yet for the PS3, and there is time to learn a lot of this new machine. And besides, remember that psmania swapped her 20GB out for a 120GB, and so far it still seemed okay (The PS3 detected it and all...).