I\'m developing a program in C# .net in visual studio and version controlling it with tortoise SVN.
at present I\'m creating the assembly version based on the build
You can use something like this to get the svn revision number.
It pretty much outputs the svn revision to a xml file then xml peeks to get the revision number.
You could perhaps use this as a pre-build event and then update your assemblyinfo with the new version number.
Also check this thread for more info SVN Revision Version in .NET Assembly w/ out CC.NET