Hopefully — The word hopefully was once an adverb, meaning it described a single verb meaning with hope (e.g., I think hopefully about the future). Now it is more often used as a sentence adverb, or disjunct, meaning it describes the entire sentence (e.g., Hopefully, I will arrive at my destination on time). The disjunct is accepted by most dictionaries.
To-day — If you read old books that have not been edited in their revised editions, you will find today hyphenated. I'm old enough to remember nondisabled and nonhandicapped as hyphenated after non. (While M-W.com and Dictionary.com accept these words with out a hyphen, AskOxford.com does not as of the date of this post.) If you can read this, then you remember email written as e-mail. Once a word becomes commonplace, we often drop the hyphen.
Literally — Many people use the word literally improperly in common conversation, as in the example. But if you try to correct them, they're likely to tell you to get a life. Most use it despite knowing its wrong. Some words just get misused at one point or another and become accepted in their new meaning. I admit to having using it "improperly" in speech, but I'd advise against using it in writing.
