Despite the fact the US PC movie store clearly states in its terms and conditions that downloaded content stays deleted if you deleted it, Arstechnica's reporting the SCEA is, in fact, a little more lenient than advertised with its DRM policy.
"If a consumer deletes a purchased movie from their PS3, they will not be able to redownload the movie without assistance from SCEA's consumer services," said PSN PR Lincoln Davis.
"Consumer service can issue a redownload as a one-time courtesy, as provided by our guidelines, for the title to allow the consumer to go back and download the movie from their PSN download list."
Don't get frisky if you're allowed to download stuff again, however: you won't be allowed to get content a third time.
Plenty more through there.