Have you used Pages recently? It’s got a button in the default toolbar to “Publish on iWork” which has never been out of beta and is now cancelled. It doesn’t work in HiDPI modes of Lion. It doesn’t support Lion’s keyboard macros. I wrote one letter in it last week and ended up filing three different bugs.

So, yes, software does “rot,” if it’s not kept up-to-date with the latest operating systems and, to an extent, the latest user interface metaphors.