"0 new features" was marketing that seems to have worked quite well. I can't remember where, but I swear I remember hearing that later from people at Apple. The major thing is they didn't do a big UI refresh. In Snow Leopard they: finally rewrote Finder in Cocoa, released Quicktime X, shipped a 64bit kernel, released Grand Central Dispatch, released OpenCL. Plus a bunch of smaller updates and tweaks. They dropped included things like printer drivers (which now download on demand) which make the install size smaller.