It's a £1000 more than I paid for the D800/D810 on release. Forget about the new sensor, 4K etc that has nothing to do with it, technology moves on and they need to offer better at the same price bracket otherwise where would it end.
The exchange rates are the only thing that may have a factor but USD 3500 = GBP 2654 today not USD 3500 = GBP 3600!
Very poor upgrade by Canon and even worse pricing.
Don't get me wrong, I would love it to be £1000 cheaper, but unfortunately it isn't going to happen. Economics have a massive play in pricing. The cost of the new sensor and introduction of 4k into a XD series camera will have to be recouped - ok 4K isn't new technology, but the electronics inside to do that aren't free. The consumer pays - if they don't like it go elsewhere.
Canon know their market and quite clearly will have worked out what they can get away with. Offering better at the same price bracket? Well they'll probably do that with the 6D Mark II, which will probably end up sitting around the £2500 MSRP mark. by the time market forces come into play
Canon aren't going to cannibalise their high end Cinema or 1 series camera and I suspect they've added about all they will do to the 5 Series - other than small tweaks to future models such as faster card slots, a few FPS extra, perhaps a bigger sensor with slightly better DR they're probably hitting a ceiling that they're not willing to breach.
As for exchange rate being virtually $1=£1? Nothing new there, we've always been screwed like that here in the UK.