If I had to guess, most of the revamped UX will come in their Wave in a Box project[1].

What we know:

a. Lars and his brother Jens have been a team or working colleagues for at least a while (maybe since 1999)[2]. They co-founded Where 2 Technologies in 2003 which got acquired by Google in 2004 and became the core for Google Maps.

b. A big proportion of the Google Wave complaints surrounded the UX, both for end-users and devs.

c. Lars on Wave "On the team after a year and a half, when we started using it, it still took us a while on how to use it... how to be more productive using it." [3] The whole video is a good watch for those interested, and so you get the context of the quote as well. We can gather that Google Wave germinated from a very organic process including the UX.

d. Google's Wave in a Box project will include a subset of the functionality (simplification) of Google Wave. "This (Wave in a Box) project will not have the full functionality of Google Wave as you know it today. However, we intend to give developers and enterprising users an opportunity to run wave servers and host waves on their own hardware"[1]

What I think but really do not know and I suck at writing:

* With Lars leaving, it adds liquidity to the possibility of further change on Google Wave development or integration. It makes it pretty certain that the leadership on the project, Wave in a Box, or subsequent integration projects will at least be tweaked. This will be further confirmed if Jens leaves as well (a), but we have no idea at this point if he will.

* Losing Lars maybe Jens maybe others and they will lose a big whack of their engineering leadership on Wave, so you can expect further developments on the core technology to slow tremendously. What's left is the community building, repackaging, marketing, open-source, maybe some hope in monetization, some more experimentation, package and publish extensible protocols[4], maybe trying an adoption experiment (Wave in a Box, maybe enterprises will use it!!!, let's fight Outlook), maybe some hope in leveraging the existing technologies with integration, etc. Google Wave's team is probably focused just on that, and the head caveat on those tasks is the UX. They'll probably bring in or already have some outstanding UX folks. Maybe the leadership on that front wasn't there from the start, but we don't know as it was created in a very organic fashion (c).

* Google is a master at integration in most cases. Just look back at all the acquisitions that went really well, and on top of that, Wave is using most of the Google ecosystem already. While the Wave in a Box project continues, you can probably expect some Google Wave functionality and technology to pop up here and there. I wouldn't be surprised if it makes an incremental and subtle appearance in some of GMail's functionality in the way Buzz has, but we don't know.

* Most of us would agree that Google Wave won't be coming back in its current form because the tarnished reputation. Such an event is more unlikely than finding a black swan, more like finding a transparent swan who can do calculus, but even finding one of those can happen. It will be interesting to see what happens with Wave in a Box, Google Wave Federation Protocol, and Google's ecosystem, hopefully good things.

[1] http://googlewavedev.blogspot.com/2010/09/wave-open-source-n...

[2] http://au.linkedin.com/pub/lars-rasmussen/5/519/16 http://au.linkedin.com/pub/jens-eilstrup-rasmussen/5/192/890

[3] http://www.youtube.com/watch?v=Nl1_MmnhJpA#t=2m32s

[4] http://www.waveprotocol.org/