The vendor doesn't even need to do anything for SONAR to support this since the vendor name is part of the plug-in metadata.  It's on my wish list for SONAR that they use this info by having an easy-to-get-to option to toggle vendor name on/off in the FX browser/menu and also include the vendor name as a field that is searched by the type-in search.  This would also alleviate the problem of fitting the full name in the bins since differentiating by vendor is less important at that point and it could just show the plug-in name.  

Sanderxpander
This goes for all VST3 plugins I think. At least I can't rename Waves VST3s either. The renaming holds in the plugin properties window but not in the Plugin manager list and not in the plugin list when you want to insert one.
 
EDIT: By the way the VST2 versions rename just fine, should you be inclined to use those.

That's the difference, then. I always use VST 2.