By separating processes for each content instance, if one tab were to crash, the entire session would not be compromised. Additionally, security can be enhanced by stripping content processes of their rights, allowing them to compute but not read from or write to sensitive areas – everything would be proxied through the parent UI process. If this “sandbox” approach sounds familiar, it’s probably because both Google Chrome and Internet Explorer 8 utilize the behavior to a degree.
The development team is being coordinated by Benjamin Smedberg, and the initial tier of the four-plus phase creation is scheduled to be completed July 15 of this year. I wouldn’t expect to see a polished release until next year, though. Phase two has a scheduled goal of November 1 and the following steps currently lack ETAs.