I've had occasion recently to watch a number of professionals at work. I know them to be professionals because they made a point of indicating it, and in some cases, clarifying it when the fact might be in dispute. In each case these people had become engaged in some larger group activity, and had naturally fallen into contributing based on their own specialty. That is, they had not been hired as professionals, but felt compelled to show up as such nevertheless.
Let me draw a distinction between expertise or competence on the one hand, and being a professional on the other: when a project needs to get done, the people who get things done are those who are able. Getting something done is quite simply the result of doing things. Does getting it done require one to be a professional? It might. No one is going to ask me to operate on their sick child simply because I have good intentions if I don't have training as a surgeon. Nor would I profess to being able. An increasing number of activities, which were once within reach only for professionals, are now rightly open to anyone willing to become competent. Among these are the activities made possible by the web, for example, writing, teaching, learning, marketing, development, media arts, reporting, politics, etc.
I try not to call myself a professional, or even to think of myself in this way, because I have observed that it tends toward a false self-image and personal misunderstanding. I try even harder to ignore those who call themselves a professional, when doing so contributes nothing more to the task at hand than a repudiation of the others (read "non professionals") engaged in the work. The only question that matters, no matter the project you are doing, is whether or not a person can engage with the content of the work. Credibility comes from being able to usefully contribute, authority from an awareness of the facts as presented, and an ability to synthesize them with past experience. The past may come to bear on the present; but the circumstances of the present will provide or deny those engaged around the problem with the opportunity to act competently. That is, increasingly being a professional does not guarantee success, or more positively, being an amateur does not guarantee failure.
The days of the professional, at least as historically constructed, are receding quickly. No longer is access to a profession the sole route to professionalism. No longer are the tools needed to engage in the work only available at work. No longer are the social networks necessary to collaborate and amplify a message or start and sustain a movement contained in a building.
I work on the open web partly because I love technology, programming languages, and digital media. However, a large part of what motivates me to work on particular things is the desire to further detach the professional from professional work. I still have a lot of work to do, but luckily I'm not alone. And I look forward to the day when being told by someone they they are a professional, to whom I must listen simply because they have been taught that this is their right, causes everyone in the room to turn around and look at who is talking such nonsense.