There's no proof that it actually worked (since I haven't been yet), but if you have your reservations linked on the main disneyworld.com site, they are allowing (for those whose computers have the luck of connecting to the site as fully as they are allowing, at least) checkin up to 60 days out. And for SSR they had checkboxes for each of the areas of the resort. You could choose up to 2 options; I chose the area I thought would be nice, and ground (or maybe it said "lower"?) floor. they also have an option of ignoring requests for the chance to check in early. I didn't check that one.
You could always print the screen for "proof".
And when I go back into my disneyworld.com account and click in to each of my reservations and choose online checkin (note that I'm currently still 12 or 13 days out), it asks if I want to *change* my checkin. So it *seems* like it has worked.
Might want to check it out.