First let me say that I understand about Lion removing the scripting extensions that made this possible before... I get all the reasons you "can't" do it... even though it seems with Fluid's userscript support there would be a way even if not as elegant.
Question instead of integrating 1P into a Fluid SSB for one-click password happiness, would it be possible to tell 1 Password to launch a particular Fluid SSB instance and login?
Normally in 1P if I click on a login it'll open that login in my default browser, I just want it to open that login in an assigned SSB instead... It's only half as useful as 1P integration, but at least I wouldn't have to go back and forth multiple times coping and pasting.