The word hopefully is not wrong, but it should be used properly, not as a synonym for "I hope" or "It is to be hoped."  Hopefully is an adverb meaning "in a hopeful manner" or "full of hope."  We can look forward to our summer vacation hopefully (in a hopeful manner), and we can read the winning numbers on the lottery hopefully (full of hope that we have a winning ticket).  However, it is absurd to say, as many people do, "Hopefully, the weather will be nice this weekend."  Does "In a hopeful manner, the weather will be nice this weekend" or "Full of hope, the weather will be nice this weekend" make sense?  What is full of hope? We may say, “I hope the weather will be nice this weekend” or “It is to be hoped that the weather will be nice this weekend,” but not, “Hopefully, the weather will be nice this weekend."  For further discussion of this point, see hopefully in the online American Heritage Dictionary. Scroll past the definitions to the usage note.