At the outset I would like to question the term Orientalism for which you have used Edward Said's definition on your site and on which the definition of "the orient" appears to rest in the context of the field of post colonial studies. This, for me, is a curious construct and one which Said may well have adapted as necessary or as beneficial for his use while being aware that this contains a questionable aspect.
The idea of Orient implies in some context the idea Occident (which Said recognizes, while choosing the term on one hand and dismissing it on the other.) In this dualism the basic distinction between the two lies not in the Muslim world of North Africa and the Middle East but at its eastern border with India.
Although the original understanding of "Orient" was made on the fact that it was east of Europe what may be understood more correctly as Orient may be distinguished from Occident by the very basic distinction of the understanding of the universe in which we live as one which is linear as opposed to circular and manifesting an understanding of time which is also linear as opposed to circular and returning. These ideas are better and more completely expressed in the writing of Heinrich Zimmer and Mircea Eliade among others.
In this construct (which is rooted in ideas of culture and not the Eurocentric view which Edward Said accepts on the one hand and dismisses on the other) Islam and the Muslim Middle east are in fact the Occident and thus our relation to them is thus in a real sense our relationship to ourselves or perhaps rather to an exotic aspect of ourselves. The many connections within the "occidental" tradition as expressed in Judaism, Christianity and Islam are extensive and profound.
A further question revolves around the question of what colonialism means and what postcolonial studies therefore are. In looking through the material posted on your website I notice that it seems to be restricted to the colonization by European countries. There are many extensive examples here, including Latin and North America, the colonization by the Soviet Union in Central Asia which were begun by Czarist Russia and strictly maintained after the Bolshevik revolution. There is as well colonialism by China in Tibet and perhaps also in Sinking, of course of course not "post" colonial as of yet.
Finally there was a Muslim colonization both in the past in countries such as India and the present, such as the recent invasion of Timor by Indonesia. One might also look at the Islamization of the countries conquered in the early years of Muslim expansion. The consequences of Muslim colonization of India which was very long, and was ended by the advent of British colonialism, still echo in that country.