Depends on the organization
The only place I have worked at which power users were both empowered and well directed was an optoelectronics manufacturing firm with strong and forward-thinking management. However, even at this firm, it was entirely likely that any task I performed (as IT-Production liason) would involve an endless maelstrom of redirection from one manager to the next because no one knew the whole organization. In order to complete tasks, I deviated from instructions, which breaks ISO9001 compliance. So, here I was part of the IT support team, but effectively a troublesome power-user with respect to the rest of the organization.
Every other organization I have worked with suffered (or continues to suffer) from a lack of over-arching managerial understanding. Basically, as an organization, we have no clue what we're doing. From my point of view, this stems from a lack of focus on the goals of the organization (to make money?), an inability to distinguish (and define) behaviors that are beneficial and behaviors that are detrimental to the organizational goal (including the security aspects of utility verses risk), and a lack of willingness or inability to define appropriate levels of service according to the organizational goal and according to the resources available.
The result is always randomness, duplication of effort, inefficient investment in resources and purchasing practices, and a failure to meet the goals of the organization - in a word, waste.
What power-users don't seem to understand is that not everyone is a power user. Given the same tools, perhaps one in ten, or one in fifty users, will use them very effectively. Adding more tools doesn't help, but may actually decrease the ability to provide effective support .
What IT doesn't seem to understand (in cases I have seen) is that in their/our role of empowering creative work, facilitating productivity, and protecting the organizational data, appropriate levels of access and appropriate levels of service must be provided. Saying "No." without organizational backing is ineffective. Refusal to evolve is ineffective. Endlessly requesting more money for IT budgets without providing an understandible cost-benefit analysis is ineffective.
It helps if the organization is directed by people who have a solid grasp of the difference between science and science-fiction.
Basically, we're doomed...