As the earlier posters have noted, it's very do-able, and a nice way to experience two different resorts in a single vacation. We've done this several times, and the major downside---from my perspective---is not having a room to call "home" for part of a day. Which is not a problem if you're planning on being in the parks all day that day, but could be if you have young kids who need afternoon naps, or if you come down with a headache and want a quiet place to sleep it off...
But as long as you're aware that you'll have to check out of one room in the morning and might not be able to get into the next one until late that afternoon--and plan accordingly--you'll have a great time. Enjoy your trip!