The current and next gen are the same price in the US, I'm pretty sure.

On the other hand in the UK next-gen games are 10 quid more expensive. Why would that be?

I'm seeing PS3 games that have always been £39.99 not being £42.99 - £49.99 and PS4 games being £45.00 to £59.99.. there greed will kill sales.
im not buying any game over £39.99 when its brand new. i will happily wait. everyone should do the same and fuck these greedy money wanglers..

any new import taxes? is it the same for wii U games

Fair point, but why do those new import taxes not apply to PS3 games imported over the same period?

Porbably, there deals already in place for those games and someone is taking the hit, just speculating. Also that might be standard for the gen sometimes you see a game for 70$ here in Canada and you see and other one for 60$ with nothing explaining why the other one is more expensive.

UK Price wars have not occured yet. In time prices will go down. RRP for PS3 games has been £50-55 all gen, alas pricing wars means game shops would rarely sell games above £45 as they know Tesco would happily sell the game for £35-40 and make more than them. But for PS4 games, they are not yet in store for this pricing war to start properly. RRP though seems to be £55-60, up a fiver. Games will settle at £40-50 new in stores.

Still a price increase but what are you going to do? Welcome to the UK, where we are already getting charged $60 more for the console itself.