Wave. Bits and bobs are likely to appear in Google products but the whole notion of Wave as the next generation, game changing product is not going to be realised.
For us Wave proved itself quickly; it was easy to produce a WYSWYG interface for MediaWiki. This generated a lot of interest in many places, it had us generate a lot of air miles and we had something to show and tell.
For us there were a few issues that were not resolved to our satisfaction. Our aim was to provide a WYSWYG interface for MediaWiki and this meant that our complete solution had to be open source. This took just too long, there were understandable reasons but it killed interest in the Wikimedia Foundation. As the Wave interface was to be used for Wikipedia, it was just not acceptable that there was no way to internationalise and localise Wave and its extensions.
I am sad that it is over, here is finally a video with Erik Schmidt talking about the demise of Wave..The sound quality is poor..