5 Crap I think. People expected a lower spec phone and a correspondingly lower price, but I don't think they've achieved that. I agree with killing the 5 in that having more than 3 iPhones officially on sale at one time may get confusing, and might make it seem too much like they're turning into iPods but the price doesn't work. From what I've seen it's a worse phone than the 5 for the same price that the 5 would've been at had they kept it. The casing looks a bit like a 3GS and I can't see it looking good in the flesh, especially as it has the larger screen and retina. Needs another £60 at least of the price I think and even then I'd still be sceptical as to its chances.
I don't think that the C as a concept works positioned between the 5S and 4S either. I think that most people who don't already have an iPhone won't look closely at internal specs and would go for the 4S: it's cheaper, looks better and as a first smartphone, the 5C screen might be too big anyway, even if it is still on the small side by industry standards.