After struggling with upload/commit transfer speeds that were absolutely crippling, I've finally managed to get an exponential speed boost for svn merging and svn committing large numbers of files.
For svn merging, see this post by the good folks at WorkHabit.org.
For general SVN transfer speed help - hop into your /etc/ssh_config file and add these lines to your file:
# Host *
Enjoy not seeing upload times of 2k/sec anymore. :-)