The Official SF4 website has been updated today with a confirmation that both Seth and the mighty Gouken are playable in the home version of the game.
The website also provide new updated artwork for both the 2 newcomers.
According to Reno from SRK forums, the web page also confirms that Gouken is not going to be playable in the arcade version.
The new artwork for Gouken and Seth (pictured above) look more polished than the initial ones that were used for the arcade version.
In related news, Shizowa San updated her blog today with some early rough sketches of both Seth and gouken drawn by Ikeno.
you can check the rest of them here