I'm not quite sure what you're trying to argue for. You seem to want an integrated way of accessing remote resources (a la SMB but for extremely remote resources), but then you seem to be arguing in favour of hiding the directory hierarchy entirely (forgive me if I'm mistaken here).
In regards to remote resources, currently there are various FUSE plugins which can present remote resources in the filesystem (e.g. flickrfs). These are of course issues with the abstraction (how do we represent tags in a hierarchy?), but the use of these plugins is mostly transparent to the user (ignoring performance). It's certainly possible to build a layer atop of these that would integrate better with the system (e.g. add a Facebook selection to the open dialog).
You also seem to want to conflate applications with the data they manage. For a large number of users this is fine (iTunes is already their music, IE is the internet, etc), but for many others this is problematic (how do you manage moving data between these applications without a common intermediary. consider scanning an image, touching it up, then including it in a document - where do the original and altered versions live, how are they accessed by applications?).
In regards to remote resources, currently there are various FUSE plugins which can present remote resources in the filesystem (e.g. flickrfs). These are of course issues with the abstraction (how do we represent tags in a hierarchy?), but the use of these plugins is mostly transparent to the user (ignoring performance). It's certainly possible to build a layer atop of these that would integrate better with the system (e.g. add a Facebook selection to the open dialog).
You also seem to want to conflate applications with the data they manage. For a large number of users this is fine (iTunes is already their music, IE is the internet, etc), but for many others this is problematic (how do you manage moving data between these applications without a common intermediary. consider scanning an image, touching it up, then including it in a document - where do the original and altered versions live, how are they accessed by applications?).