In the original Castlevania: Lords of Shadow, there weren't a lot of characters for players to keep track of. The story mostly followed the quest of Gabriel Belmont and his mentor Zobek. For the sequel, the cast has been significantly expanded.
In the latest trailer for Castlevania: Lords of Shadow 2, Konami reveals all the characters that will play a role in its conclusion to the Lords of Shadow trilogy. Obviously, Gabriel and Zobek are back with the latter being played by Patrick Stewart once again.
As for new characters, Alucard, Trevor and Victor will all make an appearance in this latest game. Alucard and Trevor were playable characters in Mirror of Fate with Simon being the only true new addition to the Lords of Shadow franchise. It's hard to say how the writers are going to keep this many Belmonts sorted out, but it should be manageable as long as they don't try to shoehorn Soma into it somehow.
Castlevania: Lords of Shadow 2 will be released on February 25 for the Xbox 360, PS3 and PC.