Somebody in this thread made a very good point a few pages back (sorry, too lazy to go back and quote it), but there's too much of an ISK faucet in highsec to make it worth going anywhere else. Between L4 missions, lots of asteroid belts, and ice belts that never depelete, why would someone go to lowsec for industrious activities? Sure, they might want a POS to do research or build caps, but that's about it.

If you want to breathe life into lowsec there are several things you can do:

1.) Make asteroid belts in highsec much smaller and limit it to Veldspar only. They will exhaust quicker and require people to go to lowsec to get minerals. Also remove the unlimited ICE FFS!
2.) Nerf the income of missions in highsec. That means both loyalty points and bounties. Make it worth it to go to lowsec to mission and force players to band together to give protective cover for their buddies.
3.) Nerf the amount of manufacturing and research slots in highsec stations.

The proposed changes to lowsec gate guns will already make it impossible to static camp entry systems for the exception of pounce campers.

Surely, this will shake the economy for a little while, but it will slowly make Eve players much more well rounded. They will have to participate in certain types of PVP more often outside of wardecs. This change would also spur mini-trade hubs in lowsec where you can sell things at higher prices than in highsec, thus offsetting the occasional losses to industrialists from living in lowsec.

You will also see fewer 1-3 man alt corps that don't interface with the community other than selling whatever it is they produce/make. I positive that if you do this there will be far less highsec ganking, lowsec dwellers will be happier because their traffic will have gone up and they'll have stiffer opposition, and you'll also show the perma-carebear how much fun pvp can be. Eve is a PVP game. It should be played like one.