I suggest running a poll on this - of course, pg probably won't care either way, but we can integrate his code into Anarki next time he bothers to release an update, ne?
I think this convention is good; I'm just somewhat concerned with the fact that foo!bar is plenty overloaded.
edit: IIRC this has been suggested a few times before already, so I think there'll be good support for this - but it means we will then have to formally standardize the ssyntaxes too.