I came across this post and wondered if there is a way to activate only a few of all of my installed plugins depending on the workspace I currently work in.
For example
A bit late answer but if you want to manage many workspaces shortcut the following tool is very simple and helpful : http://www.xdreamteam.ch/downloads/eclipselauncher/
I use it for sorting my projects by customers and workspaces, and it launch the right workspace with all the necessary configurations needed for each.