Today MSI is announcing the latest entry in the Gaming X GPU line with the Radeon RX 480 Gaming X 8G/4G cards as well as non-X variants. The main difference between the non-X and X cards is in the core and memory frequencies, with the X card having the higher performance. In return, there will be a small price difference between the two variants.
These cards are expected to be released sometime in August.
Note to manufacturers: let's get the ball rolling. I'd like an RX 480 sometime this year but so far it doesn't look like it's going to happen.