Code objects can indeed be shared.
One thing that the "recode" module does, or allows you to do, is to strip file and line number information from code objects.  This will theoretically allow them to be collapsed.

Martin, I agree the .pyc size matters.  You are right, priorities vary.  I am mainly focused on memory use, while others may be looking at disk use.  Disk use can of course be reduced by using tools like zip.  And code objects can be re-optimized at load time too using special importers.  But it is nice to be able to achieve both objectives by enabling the marshal format to preserve those optimizations that are performed on it prior to saving it.

I'm currently working on the recode module.  When its done, I'll report back and share it with you so that you can toy around with it.