Get back to us on how they handle this!
There are TONS of us that I know ordered passes online (including my entire family) out of fear that the prices would go up again; which they did.
So with that said, I think the lower price vs. the higher cost of renewing the one you got in the mail is a wash which would seem to make sense. Therefore, I'd be surprised if they actually do this for you.
I did the print-n-go thing so I didn't pay shipping but I'm sure many other people did so if this actually happens, there could be a lot of happy SP holders out there