There are usually three ways of using the terms professional and profession in reference to the military:
Professional as opposed to Conscript or Draftee, in terms that a professional is a volunteer of an Armed Service. In this sense, yes, we are all "Professional Soldiers/Sailors/Airmen" as we all volunteered to be here.
Professional as in belonging to the profession of arms, which points out that soldiering, like plumbing or dentistry, is a profession bound by a certain level of knowledge and expertise with specialized equipment and techniques - one does not simply "pick up" the tradecraft of a soldier. In this sense, then yes, we are all Professionals.
The final use of the word Professional is a little more murky and debatable. I think that the point we're debating here and the general conception of the Profession stems from Huntington's classic, The Soldier and the State. Here is a defintion of Huntington's professionalism I gave from another thread:
The military officer is first and foremost a member of his profession, a unique body within his country that possesses highly specialized characteristics. As Huntington identified, the Military Officer's professional body is defined by its unique expertise, its responsibility, and its "organic unity and consciousness of themselves as a group apart...." All the customs our military possesses such as the salute, the deference of higher rank, and total authority of command are built around the existence of this professionalism.... When one walks into a hospital, one can immediately determine the doctor as unique, part of his professional body. When one sees a military officer, one shouldn't have to try and discern whether he is a true professional or a dressed up bureaucrat or a youth group leader.
The professional Officer is one dedicated to the "direction, operation, and control of violence on behalf of the state."
Now, when Huntington defined the "Professional" in the 1950's, there was really no such thing as a "Professional Army", an all volunteer force; most nations had professional Officer Corps that led units full of "national service" or "draftee" soldiers, which were watched over by long-service NCO's (which Huntington termed more as Master Tradesmen then professionals).
Clearly, the situation is different now and I'll admit that I didn't fully buy the applicability of this outlook when I first read it and I still don't. There is two arguments that come out of this statement.
1) In modern, Western Army's where NCO and WO's are long service soldiers who add their experience to the institutional "databank", they take part in planning by being on Military Staffs, are generally getting educated to the same level as officers, and they have an active role alongside Officer's with the "unique expertise, responsibility, and "organic unity and consciousness of themselves as a group apart...." of the NCO Corps. Thus I would most certainly say that NCO's in a modern Western Military are "Professionals" in all three senses of the term.
Would the Other Ranks constitute professionals by the fact that they (should) have been transformed through basic training, and further through a sophisticated trades training, into something unique in society? Undoubtedly, the individual soldier has "unique expertise, responsibility, and "organic unity and consciousness of themselves as a group apart...." within a larger social context. All though it is stretching the classical definition of the word, I think a strong argument could be made that Other Ranks are part of all three definitions of "Professional".
2) The third model of the "Professional" designates full-time service as a necessary requirement, how does this apply to reservists? Undoubtedly, our reservists are better then the "Professional" militaries of many countries, but in many respects, the reservist is an "Amateur". In order to utilize Reservists, you have to "professionalize" them by putting them in a full-time service environment for six months before deployment.
However, what does this say with regards to full-time reservists, who do the exact same thing and hold the exact same responsibilities as their Regular Force brethren? As well, differences in a Canadian context (at the tactical level at least) are largely limited to time dedicated to training - the skill sets and responsibilities for both Regulars and Reservists are the same, it is only the "training delta" that creates a difference.
A Dentist or a Lawyer would still be considered a member of their Profession if they only pulled teeth or litigated once or twice a week, so you could make a strong case that our Reservists are "Professional" in all three usages of the term as well.
(I see ROJ covered off some of my points while I was posting)