If you noticed, in the 5th and 6th series, the vortex looked something like this:
Now, it looks like this!
But that's not all! The colors have been made brighter and better! :) But the biggest thing is, THE LOGO IS ALWAYS DIFFERENT! Above there is the opening of the first episode of the Seventh Series, Asylum of the Daleks! Below, is an example of how THE LOGO CHANGES! :D
BELOW IS DINOSAURS ON A SPACESHIP:
BELOW IS DINOSAURS ON A SPACESHIP: