With Supreme Commander: Forged Alliance being due quite soon, Gas Powered Game's have been kind enough to publish a pair of strategy guides for their much anticipated expansion. The first one is below (but won't show on the home page).

There's also a set of Supreme Commander: Forged Alliance screenshots to go with it and a second strategy guide is coming up very shortly.

Here's Part 2 which covers some of the new units.

Understanding Supreme Commander: Forged Alliance's Gameplay Changes

During the development of Supreme Commander: Forged Alliance, we sat down and went over every aspect of the game, from resource and unit balance to the capabilities of the ACU. This strategy guide covers the most important changes we made and offers a nice primer on what you can expect when you buy Forged Alliance.

One of the most fundamental changes made in Forged Alliance is that you must constantly expand your area of operations and control as much of the map -- and Mass deposits -- as possible. In Supreme Commander, it was possible to simply churn out T1 Mass fabricators and sit behind a heavily defended base. This is really isn't an option in Forged Alliance because T1 Mass fabricators have been moved to T2, and they will only supplement, not fulfill, your Mass requirements.

To support the new focus on expansion and controlling the map, we've made adjustments to other elements of the game, as well. For example, your Armored Command Unit (ACU) can now immediately build a factory as soon as the game starts; you no longer need to build resource-related structures first.

Once your factory is complete, you can immediately begin to build light assault bots or tanks and send them to harass the enemy or secure additional Mass deposits. Or, if you’d rather carefully craft your base and sit safely behind a huge army, you can start with Engineers and build up defenses and economic structures.

Another change meant to encourage expansion is the way in which Mass extractors work. T1 Mass extractors are now the most efficient source of Mass by a wide margin (when taking into account construction costs), so it's essential that you claim any open Mass deposits. You should only upgrade to T2 Mass extractors (which are less efficient, cost-wise) when you have built as many T1 extractors as possible. (And you should only go to T3 Mass extractors, the least efficient of all extractors, once all of your extractors are T2.)

Regardless of your play style (offensive or defensive), the changes in Forged Alliance encourage you to build as many factories as possible in order to keep up unit production. One commonly used tactic in Supreme Commander was use Engineers to assist a factory; that is now less effective. Instead, build strip of four to five factories, all of which are pumping out as many units as possible. When you decide to tech up, do so gradually, one factory at a time to ensure that you still have a flow of units that will help defend you against enemy attacks. This same transition should be applied when upgrading to Tech 3, as well.

In terms of the units, we've increased both the responsiveness and movement speed for every unit in the game. This change segues nicely into the overall mission of making the game more about map control. Bots are still fast moving (but with less armor) than some other units in the game, meaning that they are perfect for early hit and run attacks and for securing chokepoints and resource areas.

In addition, many of the experimental-level units have been tweaked, too. The UEF Fatboy, Aeon Galactic Colossus and Cybran Spiderbot are now "light" experimental assault units (relative to other experimentals). They're not as strong as they were in Supreme Commander, but their construction costs have been greatly reduced. (The new Seraphim Ythotha experimental also fits into this category.) Other experimental units have also been changed; the Scathis, for example,
now has greatly improved range and accuracy.

Support Armored Command Units are now most useful as frontline builders. With more armor and faster building capability, they can survive massive amounts of punishment while building structures near an enemy base. That said, their combat effectiveness is not enough to kill large groups of enemy units, so be sure to support them with dedicated combat units.