To avoid the lag in the first place, its best to try to minimize the rate that your save file size increases, by avoiding things such as mass exploration or dropping all your loot in the middle of Whiterun (I did this ). Personally, I'm sticking to small areas and dungeons and not venturing out too much or doing anything that involves mass numbers of NPCs (at least until the patch comes).

In the meantime, these steps helped me a great deal (especially #1 and #3), though none are guaranteed to do anything so don't count on it. They won't completely eliminate lag either, just reduce it.

1) Turn off ALL autosaving

2) Delete all autosave files

3) (Taken from a post on YouTube by SuperBrot008)

Set your settings on your PS3 to the following:

-Settings-Game Settings-PS Upscaler (OFF); PS Smoothing (OFF)

-Settings-System Settings-Display [What's New] (OFF); Notification Messages (DO NOT DISPLAY)

-Settings-Display Settings-Cross Color Reduction Filter (OFF); RGB Full Range (Limited); Y Pb/Cb Pr/Cr Super-White (OFF); Deep? Color Output (OFF)

Not sure which of these changes is necessary or pointless, but some of them do help.

4) If the lag gets bad, turn off the PS3 for a little bit

Doing all 4 steps will hopefully help get rid of some of that lag and reduce load times.