The SNES is a very different animal, that was one of the model consoles of all time. Considering that countless other systems (even of that generation) operated on the same exact cartridge methods used by the NES, before writing off the NES technical problems as isolated.
Actually, a little known story regarding the original Nintendo is that damned flashing purple screen problem. That was actually done on the machine intentionally--or at least, it was alleged, after it was determined that Nintendo knew of the defect and made no efforts to correct it. That is why they were forced to redesign the NES--I couldn't find any decent pictures but this is it:
http://www.emulatronia.com/maquinadeltiempo/fotos/nes/nueva-nes.jpg
I forget what happened exactly because it was so long ago, but it involved the President of Nintendo of Japan resigning afterward, if I remember. Didn't matter, because his son picked it up anyhow, but it still happened.
Blowing in the Nintendo was many people's hopeful solution to the flickering purple screen. The flashing purple screen had nothing to do with dust. Anyone who actually was alive to play NES, I'm sure, will attest to the fact that even the best kept NES machines had the blinking purple screen problem.
I wouldn't expect you to know any of this, considering you were probably 6 or 7 years old at the time. But at any rate, this sort of thing is not at all unprecedented. If anything I would consider it no big deal; I'm sure that they will replace any malfunctioning units, no questions asked, so by and large as lousy as it is to end up with a busted 360, within a few more weeks I'm sure they will iron out the kinks.