An unsophisticated little tool that I built for my own purposes which I offer to others if they have a use for it.
The DAS Assembly numbers tool allows you to set the assembly number version for all elements of a project to the same version number, and to the number of your choice, at the same time. It should work with VB projects/solutions and C# projects/solutions in VS2005 and VS2010 and/or the Express versions of those languages, and with Sharp Develop I think. Not tested on VS2012.
The details page is here.