I think i read somewhere that fiddling with the hardware doesn't automatically means you've voided your warranty. Mods to fit the second set of shoulderbuttons comes to mind. Of course, if you mod it, and BREAK IT while doing so, as in not treating it right (here darling, I'll get that soft pillow you like) or simply by doing a crappy job when doing the mod, they arent likely to fix you up. And i guess a case with a pair of drilled holes for extra shoulder-buttons should still be under warranty if the hinge breaks. And so on.
And, reading those that say they cant really tell if you have overclocked, thats true. But in al honesty. This is a enthusiast device made by a few blokes, if not in a basement, then at least not that far away from a basement. Every warranty is going to come out of their pockets. A big company have no real problem with a few 100 guys overclocking there product, and scamming there way in to getting a new product even as they rightfully voided the warranty. A couple of 100 people that does the same in this case would be a big deal... If you overclocked, and feel it wasn't related to your warranty issue, be honest and up front about it. I'm going to guess that anything other then CPU's GPU's and memory that are well and truly dead will get covered, but that is after all a guess.
I don't really see why they would say no to a warranty if you email them and say "Hey, i overclocked this thing of and on for 8 months. Last night when i was watching a movie @ 450Mhz or thereabout, the screen just went black. Sound keept going, so it seams to still work, but the screen is broken"
(On the other hand, if they tell you to return it at this point, and when they receive it it has a big star from impact damage in the screen... Guess your out of luck ;- )
The over all impression i have, is that they intend to adhere to the same policy they had for the GP devices and as far as i know, they were very reasonable.
B!