One thing I was surprised not to hear more about at 3GSM was SAE - System Architecture Evolution, although perhaps that's unsurprising as it's such a bloody terrible name. For the unititiated, it's bacially about simplifying the bit of a mobile network "behind" the base stations (RNCs, SGSNs etc etc) that manages cell-to-cell handovers & a bunch of other functions. Should help reduce latency & offer a bunch of other good stuff. It's a work-in-progress item at 3GPP.
So yes, while I heard various people talk about "flatter architectures" at 3GSM, not many mentioned SAE specifically. Maybe that's the 2008 theme?
One thing, though.... all the femto vendors were also talking about flattened architectures for their products connection into the network. At the back of my mind I'm wondering whether operators will want to have two different sorts of flatness running concurrently, or whether they'd be keener to have some form of consistent view on what replaces today's RNCs at both macro and micro scales. It's possible that the requirements are so different that some form of heterogeneity is mandatory, but I haven't seen any evidence of any commonality at all thus far.