Hey,
If you guys want to talk about scalers in general (not just HT stuff), why not consider KeyDigital 2000HD.
It's a $12,000 - $15,000 (depending on where you buy it) scaler that has SDI and component inputs.
Of course, it's in the same catagory as terranex and S&W (a bit beyond the normal HT budget capability).
The interesting thing about it is that it has been around for a WHILE - just shows you that KeyDigital had their eye on the ball way earlier than any of us though about SDI as a useful HT tool..