Cool concept but it would need to be paired with an easier profile switcher (e.g. toolbar dropdown that opens a separate browser window for each profile) instead of having to go to about:profiles
If you're looking for a way to achieve similar functionality, you might want to check out Browser Tamer. It's a nifty little app that could help you out. You can find more information about it and download it from this link: Browser Tamer - https://www.aloneguid.uk/projects/bt/
I hope this helps! Let me know if you have any further questions.
The new profiles feature is now available to try out in the current version of Firefox Nightly — the feature is turned on by default. If you want to see a video demo and hear directly from the team working on profiles, check out this recent post on Connect: