This is the basic goal of "Linked Data" (Wikipedia has a good article on this) and we're moving slowly but surely in that direction. Every entity points at a web asset, that asset contains information about the entity and pointers to other relevant assets, etc...

Bring it all together and we have... the Semantic Web.

Not yet, but I'm experimenting with the idea of automatically linking Calais named entities to Freebase topics to make that sort of data available.

Using the Freebase API you could search for this:

http://d.opencalais.com/pershash-1/5ab0a529-9a98-3332-b57a-b66e783c2ddc

and see this:

http://www.freebase.com/view/en/bill_gates