Indeed, that's the purported utility of Gmail: keep around every piece of information, so you never lose track of anything.

Does it work that well for you? How much email do you get on a daily basis?

(I work at a small software startup, SolNovus, that has been exploring this for a while, and for us, it doesn't seem to work that well in practice. Users can't always remember keywords for long-archived messages and have to resort to scanning pages of emails, even when tagged.)

Really, I think the ticket to having an inbox you don't have to organize is not to hide everything beneath the search box, however smart it may be. At some level, you need to incrementally generate queries, because the search will be imperfect. Things like search visualization methods that help incrementally refine queries, tied to more flexible and configurable machine learning, look promising.