You can never see what changes other people have made since your last commit, because to get the changes, you have to do an update

svn diff -rBASE:HEAD to see the changes since your last update.
svn diff -rHEAD to diff your working tree against the repository.
Which does send the diffs over the web, and is inconveniently slow.

(I'm not a svn user. I just agreed with the initial reaction of "that's ridiculous", and followed it up with "I bet there really is a way to do that" and looked at the manpage.)