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.