Installing service packs?

I was just wondering if anyone knows if it's possible to install a future service pack for a current product without having a service agreement? If I were to purchase SW2010 SP1 now without a service agreement, would it be possible to download and install future 2010 SP thru the install manager (say SP2 etc.)? Would it be possible to install the future SP if I had the install files on my hard drive, or would I be limited to SP1?

SolidworksGeneral