Resident Evil 5 has three new multi-player modes, which will be available via paid DLC. The new Versus modes are called Slayer and Survivor.
The US$4.99 PSN/400 MS Points patch does not add weapons or characters, so it's unclear what it actually does. According to Capcom, however, the patch doesn't simply unlock already in-game content.
"Although Versus mode makes use of the assets that exist in the game, the functionality is not currently in the game and is above and beyond the initial scope of Resident Evil 5," says Capcom. "We have never included a Versus mode in Resident Evil before, and as well as the costs of development of the feature, there's also additional bandwidth costs associated with it."