I heard there will be 10 classes

[Beef]

any info about what they are going to be? I'd imagine Lann and Fifi will be there, but what about the other 8? And will they have similar skillset/moves as the characters from MMO version?

[Umbral Knight]

They already confirmed that Karok & Delia will return. I speculate they will bring Kai and Evie back also for the variance in grounded playstyle. Beyond that is anyone's guess.

I could see Arisha, Tessa, Grimden, and Lethor returning. If Sylas came back he would have to be fundamentally different than in base Vindictus rather than tweaks.

I don't see Vella making a return since she overlaps with Lann.
I don't see Miri coming back because she is a pure fanfiction character.
I don't see Letty coming back because she wasn't popular.
I don't see Belle coming back since she overlaps with Delia.