Taking a break is fine, but it might be best to think about what kind of grad degree and what one would like to do with it, during those intervening years. It's also a good idea to stay in contact with people that could help, for example, people who might write letters of recommendation. Ideally, between undergrad and grad, one should also be compiling info on programs of interest at particular universities, etc. Of course, easier said than done.
An MFA program is probably eternally a pipe dream, but I manage to keep the option open, I think. (Well, the option minus the cost.) One day I'll convince a scholarship out of someone (probably not), get the degree, and then rest on my laurels for the rest of my life making mucho buckos off of my impeccable verse (definitely not). Dreams are good!