Amazon has reportedly released an update for the Win8 Kindle app. It's not clear exactly when this update came out, but according to the latest release notes this new version of the app has better support for touchscreens.
This release includes an in-app store for touch optimized devices along with improvements to the reading and library experiences.
Considering that the existing kindle app for Windows 7 does not have an in app ebookstore, that might make the newapp worth getting as a replacement (especially if you have a touchscreen). The older app still works on Windows 8 (but not Windows RT), and you can actually have both apps installed on the same computer.
Has anyone tried the new version of the Kindle app? I'd like to hear how it compares.