You can read the blog post by Plurk that shows some similarities in code and design. Below is one of the pictures from that blog.
Even though Microsoft shut down the Juku site, at least temporarily, Plurk isn't completely happy with that. They believe that Microsoft is just placing the blame on an independent vendor so that they will not have to be responsible for the so called stolen code. This is not the first time in recent weeks that Microsoft has placed the blame on someone else. Last month they were forced to remove a Windows 7 media and administration tool from the Microsoft Store site after a violation of the GPL.