To compare Silverligt and Google wave is not relevant in my opinion. I see Google wave as an application and Silverlight as a techniqe to produce applications.

Sure you can do what they have done but they have done it. Thats make  the difference. When the product goes alive I think it will change the social networking arena from the ground and even  other behaviour on the net.

I love Silverlight but Google wave is an application.

 Michael congratulations to the Silverlight MVP.

WAVE is an open source application, we can run it on our servers, it's a protocol, was developed by the same guys who came up with Google Maps, and will undoubtebly be extended to run on everything including my refrigerator (that part is a joke).

If anyone here can come close to the functionality that Goggle WAVE has demonstrated, remain open source, and has the development community to back it up like Google does then you can feel very comfortable knowing that you will be changing the face of communications for the next decade.   I don't care who does it first.  Call me biased but I just want this functionality for my DNN intranets.  Just my $0.02.  

I found this post by Tim Heuer about Silverlight (or RIA platforms in general) in comparison to Google Wave. I think he makes some very valid points. 

http://timheuer.com/blog/archive/2009/05/30/google-wave-forces-out-silverlight-flash-ria-platforms.aspx

I watched the majority of the keynote video and was not very impressed. I agree with Tim's points that this looks like a new better version of GMail which looks cool but I do not (yet) see a huge platform to build off of. Again agreeing with Tim, it appears to be more of a product than a platform.

I will say that my opinion is based only on what I seen in the video... time will be the true test of what the Goolge Wave will wash up onto the shore. ( Hey look its a bad pun! :) )