Not even released yet and a significant flaw is already out there with regard to how Windows 7 handles white listing in the UAC… or something like that. On the plus side, it seems that this kind of issue is something that can be detected and dealt with. So this is a good thing.
But the final line of thought on this issue appears to be that this is really a bug with the Security Essentials software. Certainly seems plausible enough. Another way of looking at this that Microsoft has totally dropped the ball and with any luck, will get this resolved with a bit of a stronger approach than it is in the current form.
At the end of the day, there is no question that people are really skittish about UAC hacks, issues, and exploits. After all, the UAC was a bit of a joke when it first came out in Vista and it took a while for that to finally settle down. Frankly, I don’t trust any OS that has me running as an admin out of the box. This includes Linux distros that do this along with Windows.
In fairness, the UAC is better than nothing. And it has been shown to cut down on the ability to install malware greatly. But as with any OS, it is not a cure all.