Tim O’Brien: “Watch your modifiers. Do not write this sentence: `Hopefully, the teacher will give me an A.’ The teacher isn’t hoping, you are. Do write: `I hope the teacher gives me an A.’ If you don’t know the proper usage of the word, `hopefully,’ I hopefully recommend you don’t use the word at all. Moreover, if you don’t watch your grammar, I must sternly warn you, you could end up president.” (via Bookninja)
That is so, so ridiculously incorrect. The adverb used to indicate the speaker’s point of view is perfectly acceptable. Frankly, anyone who says otherwise is full of shit — a statement which any reader/istener easily understands as “Speaking frankly, those who believe such a statement are mistaken.”