An image posted to Facebook and Reddit indicates that DLC for Mass Effect 3 multiplayer is on the way. The pack, currently called "test DLC", according to the image-poster, was supposedly downloaded from ME3's "developer server".
The picture shows a prize pack unlock screen with six new characters, many of them from races unrepresented in multiplayer:
According to the image, the DLC will add: "Geth Engineers", "Geth Infiltrators", "Batarian Soldiers", "Batarian Vanguards", "Krogan Battlemasters", and "Asari Justicars".
There is no indication as to whether the "Battlemaster" and "Justicar" characters will be variants of one of the established classes or something entirely new.
Mass Effect 3 multiplayer DLC seems like a no-brainer, but until Bioware speaks up we won't know if this is actually what's in store or if it's fan fiction.