Is Tributree the next, great thing in social media? That I cannot say. However, the premise is very interesting and might well be perfect for education. In short, you nominate someone for tribute in your Tributree community, and that tribute should represent a positive moment, action or achievement that others in the community should know about.
I was recently acknowledged on Tributree. No, I don't tell you to brag (OK, just a little). Instead, I wonder how this new model of social media might be used in education? I haven't thought about it but for a few moments, but it seems that a Tributree sight for your class would allow a teacher to promote the good in their students that otherwise might not get noticed.
For example, a science teacher could post a picture of a great drawing of the lab set up by one of the students and let the whole class know they have a budding artist in their midst. Or, the group of students in history who put together the best short video enacting the raid at Harpers Ferry would get recognition (and the video would be available for the whole class to see).
The little things that aren't there in the grade book could go on Tributree, letting the class and the parents in on the hidden goodies that happen every day in your classroom.