Given Syfy's track record with miniseries adaptations of novels, I'm not optimistic about Ringworld
and Childhood's End
turning out well.
But I'll take heart from something Greg Cox
told me once or twice: That even a bad screen adaptation of a novel will still bring new recognition and popularity to the novel itself, and new royalties to the author (or his heirs, if Clarke has any). So however these miniseries turn out, it's still a good thing that they're being made.