I completely agree with you guys. I'd love to see a more open area. The terrain for open lands is fairly damaged, but a few days of repair would fix that right up. Just a repaint of the brown on some the stacking hills and a bit of flocking on some messed up ones. There's quite a few War Torn Worlds pieces that go great with the "random hills" terrain (Probably because they're the same type. Heh).
A full out farm/valley fight would be awesome, but failing that what would also be cool would be a thinning of terrain from a central point. Most of the last megabattle was a dense city and everything outside was very light. If we started at a dense city and gradually opened the field up I think it would make for a cool effect, even if one side wasn't just assaulting the city.
On the topic of points, I also agree that many people having smaller points would be great (and means I don't need to buy more titans... though I could always build some Skitarii). Preparing now is definitely a good idea.