Hi JTB - for named selection sets you can currently assign a name to any selection of objects. Do that by clicking on the name line in the properties panel:
http://moi3d.com/2.0/docs/moi_command_reference11.htm#propertiespanel

Once you have assigned a name, it will show up in the Objects section of the scene browser and you go to there to do various actions like hide it, lock it, and also select it.

So using that method you can set up a name associated with a set of objects and then go select that same set later on - does that cover what you are thinking of for named selection sets?

- Michael