Warning: the following post contains exaggeration, slight ranting, and a minor lack of fact-checking. Take with a grain of salt or a spliff or whatever you need in order to not freak out if I exaggerated at your expense or showed my lack of lingustic expertise.
It's not so much the spoken name that bothers me--after all, "we" /wi/ is a basic word, if you don't like that sound, English might not be the language for you, though surely it can be argued that there's a distinct difference between the sound's usage as a pronoun and a noun anyway. It's more that it's such a blatant marketingdroidspeak invented word, again exactly like Intel's 'Viiv', like they're thinking, we are SOOO clever, watch us change the spelling of this word to look like something out of Japanese to the untrained eye and now we can be even more clever and make puns about how 'wii' are going to change gaming blah blah.. And the gall of just adding this 'ii' letter combination to the language, although I believe it once existed in cousin language Dutch (and closer to the /ai/ pronunciation mind you), I don't think it was ever in English (not counting -us -> -i Latin pluralizations), and if it was it must have been a long time ago and was probably abolished for good reason.
Plus I'll admit it, I enjoy hating on Nintendo because I think they make boring games, rehashed sequels hardly better than EA's, and worse hardware, yet the Ninfanbois go crazy over them and bash PS and Xbox for supposedly valuing graphics over gameplay.
But don't worry, it's not just Nintendo; I dislike Apple for exactly the same reason, the followers who have a totally irrational devotion to its substandard products while still carrying around this smug attitude toward everyone else. (this is coming from a former user of both companies' products)
Finally, I just have to wonder, why fix it if it ain't broke? [i.e., the name 'Revolution'; there wouldn't have been much room for complaining at all had they simply left it at that, unless maybe the console didn't end up being very Revolutionary in the end.]