I think this is likely to be a generic .NET assembly loading question, but in my specific case, I want my SharePoint Features to point to an assembly whose versioning is ass
You can use a publisher policy to redirect to the new version.
What you could do is keep the AssemblyVersion the same (at least whilst its a 'compatible major version') but use the same technique to put the SVN revision number into the AssemblyFileVersion property.
Then you won't have to keep updating Publisher Policy files.
KB556041 - How to use Assembly Version and Assembly File Version
Suppose you are building a framework assembly for your project which is used by lot of developers while building the application assemblies. If you release new version of assembly very frequently ... and if assemblies are strong named, Developers will have to change the reference every time you release new assembly ... A better option in such closed group and volatile scenarios would be to fix the 'Assembly Version' and change only the 'Assembly File Version'.
SO - What are the differences between AssemblyVersion and AssemblyFileVersion