What I want to see Ruger do is convert the existing SP101 and esp. GP100 to Titanium! That would be better than bringing back the Speed/Service/Security series, and cheaper for Ruger - same tooling, and many of the same parts (grips, sights, hammer, trigger, firing pin, transfer bar, screws, crane, ejector, etc). Only the main frame and barrel (TI with a steel insert) change.
Or just put the GP100 on a "diet" - slim the barrel out, carve a little off the frame, there's gotta be something like 10oz available. Look at what Gary Reeder does to Vaqueros on his "Backpacker" .45LC: 28oz total, with an aluminum grip frame, 4" slender barrel and some "fat" carved off the frame. That's a gun that started life around 40oz!
Something else that would lower the GP100's weight: convert the sucker to 40S&W/10mm, with moon clips! God knows it's tough enough for either. It'd lose 3 to 4 ounces just with that alone.
Man, that would just ROCK.