Google Market vs. Amazon Appstore

The Amazon App store looks good, and yes I do like the recommendations and whatnot just like regular old Amazon. My question for the big G is this, we had to check "unknown sources" just to get the appstore on our phones and download apps through them.

Recently there were some issues with some apps found in the Android App Market and this prompted google to remove apps from their store, as well as remove them from infected phones. Will they continue to do this with Amazon Store apps, or will it be a "too bad" because it's not something we're controlling, and you took the risk.

Will this fall on Amazon's shoulders?

Here are the emails I've sent to Amazon when I get word from them I'll update:

Since we are installing apps from the Amazon App Store, what will the process be if/when an app that has been downloaded has been found to contain a virus?