Not all younger people use Twitter, I've not gone over to it, I do use Facebook though. It's a 'friends' thing, keeping in contact with people I know, and not adding just anyone and everyone. I have the problem with random people trying to add me, who I might have spoken to on another forum, but thats where it stays.
A younger generation don't really have problems with that concept, there are many who like it, and a lot of us, who don't want it. A Facebook Group page does and doesn't work. It's great for updating people about events/links/sharing pictures, but sadly terrible for chatting and keeping a log of what was said, where and when and with who.
Catch 22.
But on a good ending point, good forums like this one will keep going, because you make them how the community wants it. Just keep up advertising it via word of mouth and at events.