I like the idea, but there is more than just my team that I have to deal with. This is suited to healthy startups I'm guessing, but enerprise, government, etc... all have external forces that can make this report very deceiving.
In the hands of individuals it's a good tracking tool: I wasn't really aware that I was... maybe not as happy at work as I would have liked until I took this week's survey. I'm interested in the historic data too, after I put a couple of data points in there.
In the hands of Management, let's just say I'm very wary. Management can use this data to improve a bad situation, ("You're unhappy because we schedule meetings every day at 3 and you can't get work done? Ok, let's stop doing that"). OR more likely, especially as companies grow bigger, can just make the situation worse: ("Let's have an awkward conversation about feelings and why you're not hyper happy this week / I'll blow smoke up your rear so you'll feel better, but those meetings at 3? Yeah, not ever going to change")