I think the XMB is pretty good. However it does have a few small problems.
1) We need a search feature -- one that's easy to use.
2) The icons can take too long to load -- especially when I'm searching for a certain song or video and I'm scrolling though 100's of files which results in the icons never managing to load.
3) It feels like its starting to grow to big... i mean we have - User,Setting,Photo,Music,Video,Network,Playstation Network, friends list/final tab.
Thats 8 different icons to scroll over horizontally ... and then scrolling down Network, Settings and Game all have quite a few fixed icons..
I just feel that so many icons is scary to non-gamers -- it makes games seem overly complex...