Same for me too... It seems to try and login in.... waits for ages and then you get the error message. I thought my password was wrong but I can login in to support so it must be an iTunes thing. I was able to access the store 9hrs ago when I was sitting in Gatwick Airport BA Lounge
I just tried to enable the genius thing, and it asked me to sign in. I did, but it says "We are experiencing technical difficulties. Please try again later."