8 hours ago, and it is now still at 1%. Should it be that slow? The database in question is about 750 GB, and both servers are on the same GB ethernet network.
Over gigabit ethernet, it should not be that slow. Unless the network is saturated with other traffic or something. Might be time to call in the network engineers. Can you transfer static files at high speeds between those two hosts using scp or rsync? (Or use some other technique to take PostgreSQL out of the loop and see if your network is performing as it should)
Are you seeing transfers at a constant slow rate, or are their long freezes or something? Maybe the initial checkpoint was extremely slow? Unfortunately -P option (even with -v) doesn't make this easy to figure out. So alas it's back to old school stopwatch and a pen and paper (or spreadsheet).