pixar makes painterly CG: its totally awesome

The video was the first thing I watched and thankfully in the article, the new texturing technique was explained a lot better.

learned:

• Artists can paint 2D illustrations over some frames in an animation, and the frames between will be done themselves while maintaining the same style as the other frames.
• The changing of styles is unclear to whether it's a step backward or step forward using traditional paintings instead of photorealism.
• The painting is put on top of the animation and it doesn't change the animation at all, because it was already created. It just makes it look cooler.

opinions:

• I love this new technique, and its similar to the one they used when making the short Paperman which I'm crazy about. But what I love most is that it combines the work of animators and painters and illustrators and any other kind of 2D art to be used. I think it's because I'm more of a 2D illustrator myself, and I would like to explore 3D animation more but there's a way to combine both, thats why I like it so much.
• I like this new technique and I hope a lot of people can start using it soon. But I don't want them to stop doing photorealism because thats what people like the most about animation, some shots look so realistic but more polished and defined. It's amazing that it can be created.

question:

Is it a long process? does it make rendering take longer?