In doing a bit of bug cleanup today, I found myself wanting "Obsolete" (my efforts weren't at all comprehensive). Instead, I marked them as "Won't fix", which is probably good enough. I personally wouldn't mind renaming it to "Rejected" for uniformity, since it broadly means the same thing across report categories.
Also worth noting is that while one dev may reject a feature, another may very well decide to implement it anyways (e.g. Veracity's discussion at the end of page 1 of this thread) and then change the tag. That's perfectly fine.