I think that we need more than 1000 pieces just because ... we don't have enough shapes and textures.
Sometimes you have to duplicate dozens of pieces together to make a roof that does not exist, or to use dozens of planks to make a wooden wall that does not exist either.
In my opinion, no need to increase the number of pieces in a blueprint.
We need more official content + the UGC support to easily create new content ourselves.
After that, 1000 will be more than enough ! [yesnod][up]
I agree here...
I have created a building in the workshop which is pretty huge, still it has less then 1000 pieces.
Most of the buildings use the pieces very inefficient, the roofs Angelis pointed out is a perfect example. A single tile roof consisting of 25 pieces is not how it should be. (ok that sounds harsh, ofcourse there is no other way to do it for now, but it just feel "wrong" to me to have so many pieces (and performance) spend on a roof)
Silvarret is another example. I love his buildings and he truly is a master creator, but his buildings use a LOT or parts, most of the pieces have only a minor part visible for decoration.
If we could have UGC and have those decorations as a single part it would only count as 1 piece instead. This will also greatly improve performance since less objects have to be calculated.