Is the feature to create them in this version 2.0?

Not yet...
Since Roster 2.0 has been almost fully rewritten all addons need to be recoded as well to work with the new addon system. I know Zanix has started working on the new siggen but unfortunately I do not have any eta's on when we maybe able to see the new version.

...I don't have an eta either

SigGen 1.0 is going to be quite complex on the backend and will be getting a complete overhaul on the config interface

I am working very slowly on it though

If it looks like I won't get done shortly after Roster's release, I'll convert 0.2.6 to work in 2.0