The only way it wouldn't be worth it is if you intend to go and buy a PS4 at or near launch, I have no real arbitrary figure but lets say within 12 months. If you are it might be better to wait and put the money towards the PS4 or some games for your PS4, I think many of the "classic" games will get a PS4 remake anyway. Many of the PS2 classics got HD re-releases, God of War, Shadow of the Colossus/ICO, the Metal Gear games, The Killzone trilogy and many more all got released for the PS3. They definitely will get released again when Gaikai gets sorted out in more countries but I would imagine they will remake games like Heavy Rain based on how many PS2 era games got PS3 releases. As for any new games that you might get for a PS3 that have both a PS3 and PS4 launch Sony announced an "upgrade plan" that will allow people that buy certain PS3 games that also have a PS4 release to get the PS4 version for a "significantly discounted" price to help people transition over.
Its not like a PS3 will go to waste if you go that route, its a BD player and a streaming box too so you can stuff it another room in the house to use as a netflix box or to watch movies.
Its not like a PS3 will go to waste if you go that route, its a BD player and a streaming box too so you can stuff it another room in the house to use as a netflix box or to watch movies.