I really am disappointed that Google Wave has failed. I think the Ars article does a good job of summarizing why it didn’t really take off despite the best press you could ask for not to mention Google backing it.
I’m still hopeful that the underlaying protocol can still be salvaged in some alternate clients. It really would be interesting to see it reanimated in a different form by someone else. Even if it were just added as a new account type in Mail.app or iChat and literally only provided feature parity with that tool initially, that might be a more logical progression to introducing what should be a more powerful and flexible communication protocol. This will also give users a better understood starting point and we can more gradually figure out what people what to be able to do and how they want to do it along the way. The fully baked solution the Google’s implementation provided really didn’t enjoy much user feedback to influence its development until way too late in the process.