Basically my mistake was not going through the diff file that was placed in the plugins/ folder, and re-setting the svn:externals property, and then doing an svn up. That would have resolved the issue.
I ended up getting an older sql dump, going through the sql and finding the “active_plugins” entry to see what plugins I used to have, and re-instated them.
Hi 44calshak, check your plugins – are there any issues there? No idea what might be wrong, just chipping in that I had a similar problem, the cause was that more than half of my plugins disappeared from wordpress (though the files are still there!)