I guess this happens every OpenSSH release, but I keep hoping they'll merge some of the patches from the Pittsburg Supercomputing Center.
(See http://www.psc.edu/networking/projects/hpn-ssh )
It's truly amazing how they help transfers over higher-latency links (i.e. any distance over a mile.) They also help local transfers a fair bit.
Unfortunately, for now, if you can't patch your own SSHd, you have to use commercial file-transfer software, a Riverbed, or RSA-SSHd.