It isn’t the ideal solution. But is impressive how you can do something like this in a few days. Really inspiring.
3D-Coat has 4 or 5 packing algorithms, and tools for automatic seam creation/scaling of islands.
Wow thats impressive ambi you should really develop this further since blender uv packing sucks alot atm and this is exactly what we have been cried over for so long 
Ambi, you magnificent Beast !
Im getting nice results already with this little script. You are so cool ! 
I will definately test this out some more next week.
Though, do you think it would be possible to add some padding around islands ?
Are you writting python scripts regularly ?
I tried it and its pretty neat packer I hope it will replace blender current packing or atleast take it further 
Just copy & paste the .py file to your scripts/addons folder. Then enable it in the user prefs. It should (in theory) work.