Yufra suggested adding far-portalesque random zones branching off of other zones similar to the temporal rift. These could be short and small with a weak mini-boss and randomly spawn similar to how vaults do.
Another idea that came up was to do a bunch of vaults geared towards low level players just for the starting dungeons. We could get the vault contest going again but focus it more based on what dungeons need vaults the most and try to get the new players involved (I could announce this on SA as well as in game chat). Assuming we can get a reasonable number of 'lowbie' vaults we could increase the vault spawn rate for these zones to spice them up.
The winner of the vault contest could get an artifact or unique named after them or one of their characters as a prize.
Thoughts? Any other ideas? I think some design an artifact or design a monster contests could be good too.
I'd be willing to help judge and help implement ideas of course

(And sorry, I'm sick. So if I seem scatter brained it's because I am :/)