CapCom Unity has details, while avoiding spoilers, on new Raid Mode options coming to Resident Evil Revelations 2 Episode 4 when it launches this week. They also announce the promised online Raid Mode is coming in a patch at the end of the month:

Since the game launched on 2/24, you've only been able to play Raid Mode offline; today we shared news that online Raid Mode play is planned to arrive on 3/31 via a free software update. If you've been playing since 2/24, odds are your characters are loaded with powerful skills and great weapons - by the time the update arrives, those who've picked up the disc (on 3/17 US or 3/20 EU) will have had some time to get caught up and gain some impressive loot of their own.