In update 0.9.8.296.g91f68827 for Mac OSX, you can resize the "Following" sidebar on screen right to a generous size. However, for the playlist sidebar, we're still relegated to a very limited width. Seems like it should be an easy coding fix. Please?
You can also resize the left sidebar by dragging it at the edge. It's a bit tricky because you have to get the exact position on the edge of the sidebar, but it's definitely possible. ;)