Black certainly DOES show dust easily. If you don't believe it, take a look at my computer keyboard or receiver 5 minutes after I dusted it.
Still, I want (and require) all my equipment to be black. I like it that the current Kindle is black too, instead of grey. I find grey/silver to look plasticky and el-cheapo. (Yes, I know that a black version of a silver object is probably exactly as el-cheapo or expensive as the silver one.)