Here's a set of Dante’s Inferno screenshots, some of which show off the upcoming DLC 'Trials of St. Lucia' that's coming at the end of April for 800 ms points or $9.99. The most important features looks to be a new playable character and on-line co-op play.

Trials of St. Lucia is a downloadable expansion to Dante’s Inferno. This expansion offers several firsts for the action-adventure genre: online co-operative gameplay for two players as well as a full-featured combat editor with which players can create, upload, and share custom-created Trials with other players across the globe.
Trials of St. Lucia will be released worldwide on April 29, 2010 as downloadable content via the game’s Downloadable Content menu as well as Xbox LIVE Marketplace on the Xbox 360 and PlayStation Store on the PLAYSTATION 3.

• St. Lucia – A New Playable Character – Play as the beautiful and deadly St. Lucia of Syracuse; this battle-ready angel can fly and wields all new moves and combos.
• Online Co-Operative Play – Choose Dante or St. Lucia and play co-operatively online; combine battle tactics with other players to defeat online Trials and earn a ranking on the Inferno leaderboards.
• Create Combat Trials – Create your own Trials with a full-featured combat editor, pick from new locations, create waves featuring new and existing Dante’s Inferno enemies, tune and script them, add traps, obstacles & aid… then upload and share your creations online.
• Challenge Yourself & Other Players– Download and play other players’ Trials or try your hand at beating EA’s increasingly dangerous single and two-player Trials for medals, leaderboard scores, and achievements/trophies.
• Rate Trials – Provide a 1 to 5 star rating for Trials that you play. The online community will help the best Trials rise to the top!
• Rank on the Worldwide Leaderboards – Compare your worldwide standings as Player and/or Creator.