I don't think that 2d looks crappy. Far from it. 2d is clean and attractive. You never have to worry about low-poly models. Best of all, it looks consistent across a wide range of systems.
Frankly, if Age III was in 2d, I would be ecstatic. Yes, it wouldn't have dynamic pixel shading or multi-particle refraction but it would still look nice, and I'd be able to get the maximum graphics quality on my one-year old laptop. Right now? The demo is hideous on my machine. Eye-burningly bad. Everything is jagged, the trees are all skewed, and telling units apart is difficult.
Now, some of you might be thinking "Well, it looks great on my Geforce Ultima 8700 XT, so you have only yourself to blame." And if your game does look like the screenshots, then that is absolutely wonderful for you. However, there are many people out there that don't have the option of paying hundreds of dollars to upgrade to a top of the line video card. I am one of those with the settings on Low, and as far as I'm concerned, Age of Kings is much more pleasing to the eye than this Demo. AOK has a sort of timeless quality to the graphics. AOE3, however, is going to look outdated as soon as the next pixel shader comes out.
Now, obviously this is a matter of taste, so I can't claim to speak for anyone else with a mediocre graphics card, but I can speak for myself, and I for one miss the days of 2d Graphics.
-CrazyMrLeo
all things considered, life is pretty great