Differences between 3E and 4E combats

One thing that jumped out at me while reading over Edge of Anarchy was that many of the combats featured only one or two usually human or humanoid opponents. I'm all for fighting humans rather than "monsters", but having read through (and played through) a number of 4E adventures, it's obvious that 4E combats are meant to feature multiple opponents.

Actually, I ran across a couple of humorous (well, I think they're funny) images that purport to show the difference between a 3E encounter and a 4E one:

3E Combat

4E Combat

I can see that this will be one of the areas that will require the most work for the conversion. I think I will end up combining some encounters, adding in some, and adding more combatants (minions?) to others.