1)
Fight News
Eastside Boxing
BoxRec (database of fighters and records)
2)
The Ring seems to the most popular boxing magazine in America but I don't subscribe to anything myself.
3) ESPN's Friday Night Fights seems to be hanging on by a thread, especially without Max Kellerman. Fox Sports Net has Sunday Night Fights occasionally and I just recently saw a replay of Rahman v. Ruiz (probably to encourage PPV buys for the upcoming fight).
4) I don't think it will ever regain the popularity it saw in the 60s and 70s. Horrible decisions, promoters, and greedy fighters aren't helping either. I think Mixed Martial Arts may surpass boxing as the preferred fighting sport someday. It's more dynamic and showcases fighting in a complete sense.