well if there is no sale by 4th July safe bet it ain't happening this year.
Based on what? Independence Day is an American holiday, it has nothing to do with the games industry or the rest of the world. The 4th of July is irrelevant.
I wonder if what EA said about "devaluing IP" has led to a change of attitude at Valve?
Summer packs were added to the Steam database ("Stardock Collection Pack - Summer 2012" & "1C Collection Pack - Summer 2012"), that's either for a big summer sale, or perhaps just a smaller weekend deal, but I suspect the summer sale.