Michael Reed of Linux Journal has written a review of Peppermint OS Two. His conclusion:
In summary, Peppermint Two is a respin of Lubuntu 11.04 with the addition of cloud application integration features. The default application set is biased towards software which is lightweight and fast.
When setting up the distribution up for personal use, its success probably depends on the preferred working style of the user. A user who makes a lot of use of web-based applications might appreciate being able to give them greater parity with traditional applications. An administrator might appreciate the ability to offer users a lightweight desktop with the addition of cloud applications in a consistent and easy to explain overall package.
The full review goes into some detail about the system for setting up web applications on Peppermint's desktop. Personally, I'm still not sure if the ability to open a Chromium window dedicated to Gmail is better than just opening the browser and going to Gmail, especially if you have a webmail notifier extension.
Peppermint OS: Cloud Oriented Desktop Distro | Linux Journal