Agreed this might not replace your full IDE, but it could maybe used as a compliment to your normal development for a quick update on the go, or maybe you need to review some code when your not at your desk. Also once Google releases the docs collaboration API, you'll be able to do pair programming.
I use cloud9, which has ace as the base platform as well. It completely replaced Aptana (Eclipse based fork) for me. I use it exclusively for development and it works quite well.
I don't have time to blog, unfortunately. The reason was simple, I wanted a development stack that includes as little natively installed software as possible. With just Chrome, I have everything I need. I connect via VPN to my office network. The Secure Shell extension lets me connect to my server via SSH, Cloud9 allows me to edit code, and I can see my work in the same browser. In the end, I can develop on any machine that has a modern browser installed.
