This is essentially what was demonstrated in NRC's prototype they have shown in the Linked UI concept: http://research.nokia.com/research/linkedui

I see no problems for doing this, except in existing GNU/Linux environments you rarely have all information available in unified way. In Maemo 5 some attempt has been to provide common data store and access through Tracker. Hopefully, this will get to larger use among apps as Tracker continues to evolve with Harmattan.