Most of the changes lately have had to do with services like ManiaHome. A new service was added called ManiaFlash just a few days ago.
Also there's a redesigned Player Page
with access to your ManiaHome messages from your web browser.
I think Nadeo is saving up some of the biggest changes to really give us a nice big juicy update. As Demented mentioned, ManiaPlanet 2.0 is much anticipated and it has been hyped by some of the folks close to Nadeo for the last few months now.