Certain maps, MUST be push maps. Thats just all there is to it in my opinion.

"Munchkin: One who, on being told that this is a game about politics and intrigue in 17th century Italy, asks to play a ninja."
— Andrew Rilstone

Personally I hate the conquest mode. It's a vile creation that needs to be banished forever, I nick name it the Merry Go Round, as that’s all it ever is!

Mapping is something I feel really passionate about. Being a counterstrike mapper for about 3 years I’ve had a lot of experience in the matter of map design.

Personally I find most game companies insult the average gamer’s intelligence by creating uninspired and dull maps. The map is simply a platform for the units and weapons to fight over. That imo is completely the wrong attitude to take. Gamers want to think on their feet to get past an obstacle, not simply outgun it, it’s far more rewarding.

If you have a lift, you should be able to blow up the lift, or destroy its power supply. That would disable the lifts use until repaired. This can be an action to slow down a defenders reaction time, or stop the attacker from using said lift and forcing them to take a different route. If you have a door in front of you, you should be able to, blow it up, hot wire it, or get to a special console and open/close all doors manually. You should be able to blow up power generators to stop lighting/power getting to specific areas of the map. The map needs to continually evolve to keep you thinking on your feet.

I wasn't really regarding engines, just talking about map design in general. I can't think of any game so far that has had that level of map interaction, and looking at the near release games, none are going this route bar perhaps Crysis.