Simply, no. GTA4, RDR, Infamous, Arkham City, all games that have open worlds with better graphics than Skyrim and run buttery smooth on the PS3 and don't even require load screens. It's simply bad coding on a bad engine. There's no excuse for memory leaks aside from laziness.
From a technical standpoint they are different. That's the truth of the matter.
GTA 4:
http://www.youtube.com/watch?v=YhA2h8Edmqw
Graphically inferior in many ways and still experiences lag.
RDR:
http://www.youtube.com/watch?v=drftoCiia-o
Graphically inferior, desolate environments with nothing in them, and still lags from time to time.
Infamous:
http://www.youtube.com/watch?v=i2nI3e7u8yU&feature=related
Same story, over and over. Lag and graphically inferior in most ways.
Arkham City:
http://www.youtube.com/watch?v=c4cgTLEPiAw
This is about as good as it gets on this hardware, and it still lags.
Skyrim:
http://www.youtube.com/watch?v=3D-82B0UVCw&feature=related
http://www.youtube.com/watch?v=VWiMufFPRtM&feature=related
Is very impressive in comparison, has better graphics, and runs pretty well.
Still, hardware is what slows down the frames. If it wasn't, we'd see Playstation 1 and Regular Xbox games looking like Skyrim, but they don't because there are hardware limitations. The fact of the matter is that we need new hardware. Some optimizations might make the game run a bit better, but even 10% FPS gains will only equate to 3-5 FPS difference. That's all you can expect. They may be able to smooth some of the experience over, but it's always going to lag because the hardware is literally being maxed out. Fact.