Here is force.com from Salesforce. As far as i am concerned, the way a marketplace should look like. Already more than 800 apps available, more than 70 of them are financial apps.
Also have a look at the US Government marketplace.
Everything’s up there. With pricing info, liability clauses, shopping basket, etc
Some believe building an application marketplace is something exotic, and if your not an Force.com, Apple, Google or the US Government it is something that is years away.
What is even more interesting in this article is the video from Citrix Dazzle solution, embedded below:
Search for a financial application, make sure you get the right approval level for being allowed this app, mix and match online and offline apps, etc. It’s like an iTunes for apps, but then in an enterprise environment.
Can’t wait to see an out-of-the box offering that allows me to set up a marketplace of financial services in the cloud.