Supposedly, Ryback defeating the Big Show at Elimination Chamber is the way they're gonna "build up" Ryback for Goldberg.
I've kinda shifted opinions on whether I'd want to see this or not. If it really did turn out to be a typical Goldberg squash that lasted no more than five or so minutes and only served to further bury Ryback, then I'd be all for it. Still though, if I were Goldberg and I'm someone who was at one time one of the biggest wrestling stars on the planet, I'd personally feel insulted being asked just to come back for a quick match with someone of Ryback's stature instead of being in a more high profile match.
I get the feeling that if Goldberg doesn't return, they'll have Gillberg make one last appearance and get squashed by Ryback just as a way of mocking Goldberg.