This doesn't come as a surprise to me. Artists grow as artists due to their experiences and so their music should evolve to. It could be a good thing.
I hope they get a team (not specifically Xenomania, because what Adam said made sense) together that can give them that specific sound they used to have that made you recognise GA... while still listening to a completely different song than they had previously released. A team that is able to combine 'their' pop with different music styles so that we can enjoy listening to a revived, but still trusted, Girls Aloud.
Think nearly everyone would love a TU part #2.. or even better! I'd love songs with rock/Drum-'n-Bass (DnB, pretty popular right now) influences like SOTU, midtempo tracks like Call The Shots & music mixed with other styles such as ska (Control of the Knife), songs inspired by earlier the 1930s - 1960s with a modern twist to them, original pop like Biology and Swinging London Town...

Ohh keep on dreaming.
No generic sh!t like All Fired Up from The Saturdays (no offence TS fans) please. Or most of the music present in the charts now, really...