Yea, destroyable buildings are cool, and I see the "coolness" of what Talon is saying there, you could potentially make a certain building block off access to another point, which would be very useful for a map with defenders. They could blow something up and block a road that they have lost control of.
*IDEA*
I assume making too many destroyable buildings would cause a lot of lag, but making only certain parts would probably cause less, am I right? What I mean is can you make the tops of sniper towers destroyable? Rendering the tower useless.
Another thing I mentioned back in the SF mod was with large buildings it would be really sweet if there were cracks in the buildings that could be blown up creating a doorway into it. Probable wouldn't be too hard too, all you have to do is cut a hole in the original model and plug in a destroyable thing in its place 
And hopefully we will see the return of destructable bridges in FS. But please make them much more powerful...
"Munchkin: One who, on being told that this is a game about politics and intrigue in 17th century Italy, asks to play a ninja."—
Andrew Rilstone