Power Users in Windows are Potential Administrators

Jesper Johansson's post:

Power Users are simply Administrators who have not made themselves Administrators yet. There are access control lists, privileges, and other settings all over the OS that allow them to do so. Making someone a power users only makes it marginally more difficult to shoot yourself in the foot. It does not actually limit their privileges, nor does it protect them from malware, which can typically run just fine with Power User privilege.

and Mark Russinovich's detailed explanation:

I’d now finished the major phase of my investigation and just confirmed what everyone has been saying: a determined member of the Power Users group can fairly easily make themselves full administrator using exploits in the operating system and ones created by third-party applications.

I felt over the time that microsoft is reducing power of 'power users group' step by step and pushing it down to not be so close to 'Administrators'. By the way I must say that putting someone in 'power users group' is better than giving him the Administrative privileges; And then I must emphasize that 'Power Users in Windows are Potential Administrators' again. Mark Russinovich's post is really informative and insightful. Yet another must read (YAMR).