Root privileges are required if you are installing into a directory that requires root privileges to write to that directory...ie. /usr/local .
Also, just as an FYI, I see that you are on a 64 bit OS...which is fine...but the current version of the SlickEdit plugin will not run in a 64 bit JVM. It requires a 32 bit JVM. The next major release of the plugin (Summer 2011) will support a 64 bit JVM.
- Ryan