NXE > XMB
NXE is a pretty big improvement over the old 360 dashboard, and that was better than the XMB too, back in the day. The XMB still lacks far too many features we take for granted, such as integrated unified friends list, proper musical selection during any game of your choice, realtime voice/messaging irrespective of what you are doing on the console, integration with online content, universal achievements/trophies for every single game, and so on. The PS3's interface is somewhere between the first Xbox and the 360. It's good, but it's far too late to make the important changes now. It had to be implemented at the console's launch, but Sony failed to catch on.
You will never ever see the featureset of the XMB reach to the level of the 360's dashboard/NXE. You would have to wait for a PS4 for that. The fundamental differences in terms of memory usage and integration with the software library is too large and nigh on impossible to retroactively fit.
Even the worst Xbox 360 games have a far more intuitive and better online interface and layout than the best of PS3's works, thanks to the impecceble integration and seamlessness. Metal Gear Solid 4's online segment for example is a complete mess requiring individual Konami accounts as well as your PSN account (it's also at the mercy of the third party servers, something Sony has no control over), while games like Barbie Horse and Ride or whatever is straight-forward and hassle free.