Google Wave source code
You can extend and embed Google Wave using the Google Wave API ; however Google Wave is itself a Google Web Toolkit application and its source code is not available to the general public, AFAIK.
a source to share
As noted, you probably want to embed the wave on your blog rather than copying the entire source.
However, if you want to set up your own wave service, you can do that too . Waveis actually an open protocol to encourage widespread adoption. They hope to get us all out of this email, God bless them.
a source to share
The Google Wave has not been discovered. You can check Google OS code suggestion here: http://code.google.com/opensource/
a source to share
I believe it is open source, available from the "wave-protocol" link. This is actually a walkthrough of the codebase: http://www.waveprotocol.org/code/wave-model-code-walk
a source to share
a source to share