i personally think it is over done and badly executed.
To do this, here are the steps you need to take in Photoshop/Gimp/your image editor.
1) Duplicate the background layer.
2) Desaturate the new layer (i.e. turn it black and white)
3) Add a layer mask to the desaturated layer. Fill it with white.
4) Select the black brush and paint onto the layer mask the parts of the photo you want to look in colour.
5) When you're satisfied, flatten the image and you've got your selectively coloured photo.
Hope you found that helpful.