|Image Source: Everything2K|
Well these look interesting! When you apply the top coat the polish changes colour. It reminds me of these textas I had as a kid that did the same thing when you drew over them with the magic texta. From the picture of the brush it looks like it's a normal brush size so it would be hard to do delicate designs but you could always use a nail art brush instead. I wonder if you can stamp with it?!
These will be available in December 2012.