Most of the web users love to use Firefox because it is the greatest browser still present in the world. You may have faced same experience as I, which is same pc same user accont used by many users. We are going to experience clouding world and we are not depend on the Machine os. Recently Google also announced they are going to make chrome os as a web os. Though there are lot of Web Operating Systems we are not familiar with them as we do with firefox. Of course firefox is not a web os but it seems like one of that. Amazon cloud supports only on Firefox. There are lot of add-ons which make Firefox as webtop.

So I think its better if Firefox works as a normal webos. Then anyone who work on same user account in the same machine will not be a issue when dealing with the web. Firefox will handle all the user based settings. Users only have to log to the user account of the Firefox and customized profile will be prompt to the user by Firefox.