One of the most popular online real time strategy games of the moment is World in Conflict. HardOCP dedicated an article to this game to explore the performance in DirectX 10 and the image quality.
A few consistencies have shown themselves, such as enhanced shadows in DirectX 10, but the differences have mostly failed to impress us. Of the games we have seen, Call of Juarez made the most impressive use of the new DirectX technology, and Lost Planet offered very little improvement by comparison. BioShock was somewhere in the middle, using DirectX 10 to produce some noticeable rendering differences, but at the somewhat significant cost of disabled AA support in DirectX 10. Now we are turning our sights to a new entry in the DirectX 10 gaming catalog: World in Conflict.
Check out the report at HardOCP. Like with most DX10 games the site concludes the DirectX 10 mode isn't really worth it. The DX10 mode does offer some very nice shadow cast by the clouds and other visual improvements but the problem is that this causes a 30 to 50 percent performance drop.