European PSN releases frequently occur the same week as North American PSN releases, so it's entirely possible the Trilogy will be out today in America on PSN. We're checking with Ubisoft.
As for the retail version, the latest we've seen is September in America. The European PS Blog says the Blu-Ray release will happen "at a later date."
Update: An Ubisoft rep tells us we won't see Splinter Cell on PSN in the US today.