With 2.0 and 3.3 updates, respectively
Sony is bringing themes to PS4 and Vita with upcoming firmwares 2.0 and 3.3, respectively. The themes offer you a chance to customize your Vita and PS4 home screens with wallpapers and associated icons.
My PS3 has been set to the same theme for years, the Fang theme that comes when you get the Treasure Hunter trophy in Final Fantasy XIII. Yes, I did that. Yes, I regret it. Using that theme is a constant reminder. Not sure I need a Vita theme given all the time I spent accumulating like thirty awesome wallpapers already, though.