It's great to hear that SR4 is doing good. It's not perfect but I've had a great time with it. And the modding community is starting to take shape so it should be very interesting to see what comes out once the official tools are available.
I'm almost at the end of the campaign but I hope that they continue with the super powers theme for the next SR game. They've pretty much opened pandora's box with it in this game and there ain't no going back now that I've been able to glide across the city and do a "Death From Above" Superman move that ends with a small nuke at the point-of-impact.