Strategy & War
The two old factions, the Allies and the Soviets, have remained pretty much in their usual roles throughout the series. The Allies are solid defenders with a pretty good set of all-around units, while the Soviets are highly aggressive with expensive, but devastating units. The Allied units are the good-guy units with heroic voices and the Soviet units are the bad-guy units with Russian accents and lots of slogans. They haven't changed all that much, but that's a good thing. They were solid to begin with.
Naturally, the Empire is built entirely around armies of giant city-smashing robots. Most of these robots can transform into a different form in order to take a different role in combat, but they're generally weaker than the corresponding units from other factions. The Empire fits its role in the plot. It attacks quickly, spreads like a weed, and acts like a general nuisance to the opposition while capturing territory. It adds a lot to the strategy of RA3, which makes it a welcome addition.
What's your role in all of this? You get to play "The Commander" who tends to be the only person in each faction who can get anything done. This is probably because you are the only general with the ability to freeze time and resume battles from that frozen location at any time. Thinking about it, there's really no way you can ever truly lose. In any case, The Commander gets all the most important battles of the story with everything else moving around you in ways that sometimes ignore the fact that you won. It goes without saying that you have to win in order to move the story forward, which means that whatever faction you're working for will take over the world.
As an added bonus, you can even take over the world with friends. There have been some problems with the EA multiplayer servers in the previous releases, though. There have been connectivity issues, ridiculous lag at times, and a lot of the games have had their online player base fade away. This has remained consistent since the earliest titles released through EA. Will EA get it right in time for the Macintosh release of Red Alert 3? Only time will tell.
However, there is a lot to look forward to on the single-player side. What will you get? You'll get cutscenes with an all-star cast (George Takei (Star Trek's Sulu), Gina Carano, and J.K. Simmons, to name a few), beautiful graphics, a giant city-smashing robot, dozens of unique units, the ability to play campaigns with a friend, and a third faction to join the craziness. The PC release has been widely accepted, and the Mac release has been slated for March. There's no telling how well something has been ported until you get the chance to give it a try, but it should be worth the wait. Just make sure you don't get on the bad side of a psychic schoolgirl commando.
Command & Conquer: Red Alert 3 can be pre-ordered by heading over to GameTree Online.