I know that the graduate program for writing seminars at Johns Hopkins is very prestigious, but I was wondering how much of this prestige also applies to the undergraduate program?
http://college.usatoday.com/the-10-best-american-colleges-for-writers/
JHU came in at number 3 in the u.s., seems pretty “prestigious.”
Just to add on, as a general rule a school’s undergraduate and graduate rankings for a specific subject will be pretty similar.
Don’t know if you’re still looking at schools, but the WS undergrad program is quite prestigious and really high-quality. The professors are top-notch, well-regarded writers who have published in The New Yorker, Tin House, Best American Short Stories, Granta, etc…I mean, we even have Andrew Motion, the former poet laureate of Great Britain, as well as Alice McDermott, who won the National Book Award. In my experience, they’re all lovely people who are interested in helping students rather than hurting them. Other programs have reputations of pitting writers against each other and having faculty who belittle their students (cough cough Florida), but WS puts emphasis on fostering a supportive community of writers, and I can’t begin to emphasize how valuable that is.
Also, as a current WS grad student, I can assure you that I won’t be teaching you! We teach Intro to Fiction and Poetry for non-majors, so you’ll only be taught by the best. 
Also, even though the professors have grad students to worry about, there’s only eight of us per genre, and my workshop professor is always talking to us about how much he loves his undergrad students! If you have any other questions, I may be able to answer them, so feel free to ask!