Interesting thread this. Urban Bassman's post is especially interesting, I often wondered what was going on behind the scenes between the BBC and the Nation estate.
Phelings is almost certainly wrong about the Daleks not being missed, but is probably right when he implies that Terry Nation received too much credit for the Daleks success.
As Urban says, it was the Daleks that made Dr Who a success, no question about that. Before the Daleks, Dr Who had been met with unimpressive ratings and critical rejection. The Daleks changed all that, literally overnight. I think you had to be there to appreciate the effect. After The Mutants, the overall reaction was so positiv that Dr Who was saved from being quietly dropped. And a bit later, it was Dalek Invasion of Earth that took Dr Who to the next level, and assured it's cult status. Indeed, the Daleks will probably be remembered as sixties icons long into the future by historians who have otherwise little interest in sci-fi TV programmes.
And their appeal today is still very great. They are still THE quintessential Dr Who monsters. They still receive praise from all quarters. Children love them, critics love them. Even people who aren't sci-fi fans love them! Lorraine Kelly, for example described them as "the best TV monsters ever." If Dr Who survives, it's unthinkable that the Daleks won't make a comeback sooner or later. The public and the media will demand it.
Ray Cuisack was really the creator of the Daleks. Terry Nation wrote the original script, but it wasn't actually that original (it was really just a re-write of HG Wells story "The Time Machine"). It was the designer's interpretation of the (very basic) Nation description that made the Daleks into the great iconic success, of that there is little doubt. And, John Flawbod, I don't agree that Nation wrote the best Dalek scripts; that honour surely goes to David Whittaker, the writer in the late 60's. The Daleks were at their most cunning and most deadly when Whittaker was at the helm, imho.
Nation deserves a little credit but his hold over the Daleks is not morally justified in my opinion. And if he did indeed insist on continually using Davros, then he also has a lot to answer for. Davros was OK for "Genesis", but the process of continually resurrecting him devalued the Daleks, and reduced Dr Who's credibility, providing ammunition for the programmes enemies, such as Mr Michael Grade.