It looks professional!
The text imo is not ideal. Grandiose claim first ("operate the whole world economy") - that is a bit much and demands a lot of explanation and specification when such a claim is made. Said this often here. Maybe this is a European thing. If someone makes grandios claims that makes him look like a scammer. May be different in other cultures.
Bitshares could help to "operate a new type of economy" but when such a claim is made it should be explained. Reputations systems, smart contracts, BitAssets, UIA - all those things combined can justify the claim. Nothing worse than claims without justification/explanation.
The volume Bitshares can handle at the moment is far from those of all the exchanges named.
IOUs can not only be used for stocks.
The target audience is not clear: If it can not address both it should be either directed towards the end consumer mass or crypto people.