The problem with trying to 'top' Bloomberg isn't so much in making a better (all encompassing) product; it is more in trying to convince the legions of users and financial companies to make a change.
The world of finance is terrible slow at adopting new technology (I know a lot still use XP, sadly). So first, you have to convince people to upgrade. Then the next fun part: actually doing it. 1) fund the change. 2) get the gigantic IT departments to implement the change. Not so easy.
Then, will users even want to use something else? The finance world still uses Blackberry!