I just looked at this to clarify. From what I can tell it will not do the 720p -> 1080i cross convert. That was a function of the older boards software converter which does not exist in the newer board.
But both Decklink Studio and HD Extreme 3 will do SD to HD up converts. There is one caveat. On the PC these boards will only up convert to 1080i59.94/50 where as on the Macs they will up convert to 1080i59.94/50 or 720p59.94/50
It is also worth noting the that Decklink HD Extreme 1 and 2 will do the 720p -> 1080i cross convert as well.
I am not sure if there are plans to add these feature back into the newer boards.