What is the difference between an hourly employee and a professional?

In my opinion, a reliably performing hourly employee should scrupulously follow instructions. By no means is a professional limited to following instructions. A professional is expected to troubleshoot, anticipate, and learn on the fly.

That was the short form. Below is a more verbose version.

It is an interesting question. In academia, the professed product of the system is a well-rounded and capable human who shows competence in comparison with his or her peers. In the corporate world, research must yield immediate fruit. Knowledge for the sake of knowledge is shunned. A corporation must be profitable first and always. Treatment of employees can be a half-hearted afterthought. Apple and Microsoft have given us a new standard. The "nothing is too good for employees" attitude has created, among other things, a cultural rift between permanent and temporary employees. A more wide reaching effect of the reputation of Microsoft's and Apple's pandering to the employee has been a the proliferation of similar practices towards software developers primarily among Internet startups (dot coms) and more tentatively in more traditional brick and mortar corporations. 

From my experience, corporations would like to spend as little on training as possible while maximizing the return for the wages paid out. Under productive workers are the bane of profit. The way it works with small companies with little capital is to try to hire the most competent individuals possible and expect their passion for their work to result in a portion of their free time being spent in honing their skills, some startups off very attractive future prizes for dedicated work performed. At one point Microsoft was making several millionaires annually when their stock was splitting so reliably. This can lead in the case of failed startups to much wasted effort and the crushing of dreams. As stated before there are instances to belie this grim fact. Carried too far, this results in overspecialized automaton-like employees who haven’t got enough flexibility or autonomy to easy jump from a dead-end job to a plum assignment.

Human beings are machines in only the most bleak and shallow view. Our creative problem-solving and intuitive leaps outclass any machine designed, built or imagined. Where productivity is the bottom line, I feel that prioritization rather than strict scheduling could yield better profit. To be sure, there are many jobs that require absolutely on time delivery of work. I'm including the more support call centers in this category. It can be very difficult trying to balance personal goals with the demands of work, especially when tasks assigned in the workplace seem uninspiring and redundant. I think an aspect of professionalism is doing your work without acrimonious compliant while figuring out an innovative way to make the tasks enjoyable, i.e. whistle while you work. Another approach is to try to automate as much as possible. The danger here is that the more complex and proprietary you make systems (using system in a very loose sense of the word here) along with inadequate documentation, the greater the chance that unexpected changes (organizational and technological) can have devastating effects on the level of service you initially thought to automate into a smoothly running and out of sight process. I feel that a professional should care enough, if not about the corporation then about the quality of their work, to leave an orderly environment for his or her successors. This is akin to a rule in the Boy Scouts of America to leave the campsite better than you found it.

Professionalism also applies to interpersonal behavior, hygiene, and manner of dress. Companies with loose dress codes allow their employees to express their personalities, culture, and flair. We are not robots; individuals need to express themselves in the form of their appearance. Any abusive behavior or intolerance for others is a violation of professionalism. That seems to be implicit in being human, but it seems that many people in the world are not in agreement with me on this one.