@cdpenner You may require a different Tuner/PVR. I recall upgrading to BlueSky(BlueCurve) and requiring a new tuner/PVR. This was done at no charge when I upgraded my plan. I would ask Shaw that question directly.
@cdpenner -- within this discussion forum, @rstra has stated that you will need one account for the BlueCurve PVR, and another account for any of the older PVRs (Shaw Gateway, Pace, Motorola). Strange, especially because the one coaxial-cable into your home carries both signals, but I have no reason to doubt his statement.
Ya, the legacy and BlueCurve boxes are on separate billing systems. The cable infrastructure in the home can handle both systems, but would require another account.