I was at a customer site recently. And because I'm on the SWAT team, let's say that the situation I dropped in to help was a little tense. And it just so happens that I have a daily build of the Notes Social Edition as my client.
Someone had come into the war room and was demanding some answers on an aspect of what the team was doing. During a period of intense "back and forth" that I was in the room for but not a part of; the mood suddenly changes. Suddenly the conversation becomes easier going and there is a lot more agreement. After he leaves, about half the room remarked "Did you notice he couldn't keep his eyes off Michael's computer!".
Apparently, he saw me moving through the new UI and was enthralled. I'll take the help where I can.
Probably the most talked about piece about the Social Edition is the plugin. It allows more integration of applications into the browser so that you can view things other than mail with your browser.
BTW, below is a screenshot of a beta build I took from Ed Brill's blog. The layout is cleaner and you get a lot more information without feeling cluttered. And they have made some really smart improvements to how to navigate around. I can see why one might be enthralled.