The answer is a definate YES. I bought a used SP300V from a fellow s101 and he still had 6 months left on the warranty....transferred it over to me and I reupped it when it was about to expire.
I did go through the Roland tech rep to do all this, since by yourself it might be tough (since the rep I think has to inspect the machine and make sure all is well before it is transferred).
Whoever they bought it from should be able to do the same as long as some time is left on their warranty.
Good luck, great machines those Rolands!
-Matt