Ryu from Street Fighter is Asura's Wrath DLC.

Capcom Japan teased the announcement with a screenshot, below.

It shows Asura from Asura's Wrath squaring off against Ryu from the classic Street Fighter side-on perspective. There are health bars, super meters (or in Asura's case, a burst meter) and even character portraits at the top of the screen.

It's unclear at this stage exactly what this DLC will provide - is it a full on Street Fighter 4 mode for Asura's Wrath, or cut-scene made to look like one?

 Capcom promised to reveal all soon.