(This post was inspired by Lance's post on Zero Knowledge, here, which was inspired by a video he has in the post which was inspired by... (I think this ordering is well founded.))
ZK= Zero Knowledge.
When it was shown that NP \subseteq ZK this was a big deal. This was by Goldreich-Micali-Wigderson (see here (FOCS-1986, JACM-1991). In the JACM paper they have the following passage:
Our result that all languages in NP have zero-knowledge proof systems, has been extended to IP, assuming the same assumptions. (The result was first proved by Impagliazzo and Yung, but since their paper  contains only a claim of the result, the interested reader is directed to  where a (different proof) appears.) In other words, whatever can be efficiently proven can be efficiently proven in a zero-knowledge manner. This may be viewed as the best result possible, since only languages having interactive proof systems can have zero-knowledge interactive proof systems.Later the papers of Lund-Fortnow-Karloff-Nisan and Shamir showed IP=PSPACE. Hence
11. BEN-OR, M., GOLDREICH, O., GOLDWASSER, S., HASTAD, J., KILLIAN, J., MICALI, S,, AND ROGAWAY, P. Everything provable is provable in zero-knowledge. In Proceedings of Advances in Cryptology— Crypto88. Lecture Notes in Computer Science, vol. 403. Springer-Verlag, New York, 1990, pp. 37-56.
53.IMPAGLIAZZO. R., AND YUNG, M. Direct minimum-knowledge computations. In C. Pomerance, ed., Proceedings of Advances in Cryptology— Crypto87. Lecture Notes in Computer Science, vol. 293. Springer-Verlag, New York, 1987, pp. 40-51.
When I realized this I thought OH, that's interesting! I then looked around the web and could not find any mention of it. I asked Lance and some people in crypto and yeah, they all knew it was true, but nobody seemed to care.
Why the apathy? Speculation:
1) ZK is a notion people actually want to use in real crypto (and there has been some progress on that lately). The prover for ZK in PSPACE has to be way to powerful to be practical. I don't really like this explanation since we are talking about theorists. Even in crypto, which has more of a connection to the real works then, say, Ramsey Theory, there are still plenty of non-useful results.
2) IP=PSPACE was the big news and had interesting proof with nice ideas. Nothing crypto-ish about it. So the corollary that PSPACE \subseteq ZK is an afterthought.
3) SAT in ZK was big news. IP in ZK is nice, but uses mostly the same ideas.
4) I am WRONG- it is a celebrated result and I somehow missed the celebration.
5) The proof that ZK is in PSPACE USES two interesting results, but adds NOTHING to the mix. In short, the proof is to easy.
Any other ideas?