Foucault and Hegel

In my big Marx, Hegel, Feuerbach post I try and describe Hegel's conception of Geist by saying it is a lot like Foucault's notion of discourse. Looking through Foucault's candidacy presentation to the Collège de France, I found he himself also obliquely makes this comparison:

To the extent that, in a given period, [knowledge] has clearly specified forms and domains, it can be broken down into several systems of thought. Obviously, it is by no means a matter of determining the system of thought of a particular epoch, or something like its "world-view." Rather, it is a matter of identifying the different ensembles that are each bearers of a quite particular type of knowledge...
-in Ethics: Subjectivity and Truth, 9

Foucault is suggesting that Hegel is so abstract that he approximates the "sprit of the time"-type analysis, but at the same time he is suggesting a kinship between them, in that they are looking for a level of knowledge that is not localized within specific fields (biology, math, etc.) nor in the mere objective institutions that constitute these subjective domains (prisons, universities, police... etc). That is, Foucault to an extent engages Hegel in engaging a fundamental theoretical problem:

...the theoretical problem of the constitution of a science when one aims to analyse it not in transcendental terms but in terms of history.
-in Ethics: Subjectivity and Truth, 8

This is a good way to take Hegel most of the time, even though he is engaged in a transcendental project. In the end, the following definition of discourse in Foucault's seminar on the "will to truth" comes, therefore, surprisingly close to a concrete sense of Hegelian Geist as it is active in history:

Discursive practices are characterized by the demarcation of a field of objects, by the definition of a legitimate perspective for a subject of knowledge, by the setting of norms for elaborating concepts and theories. Hence, each of them presupposes a play of prescriptions that govern exclusions and selections.
-in Ethics: Subjectivity and Truth, 11

This language of exclusion and prescription is the underlying concrete sense of what Hegel often says. In final analysis, the conclusion we are suggesting here is that Spirit is like discourse minus the (incredibly significant, for Foucault) imbrication of discourse with the Nietzschian concept of power. It should be noted that the inclusion of this language brings discourse closer to Heidegger's "understanding"--to the point where it can even be said (and Hubert Dreyfus indeed does say this) that they are almost identical concepts.
But in the end it remains a matter of thought whether we've levelled off both what Foucault and Hegel have said to the point it no longer carries any meaning. I would suggest in the end that thinking of Geist as discourse is useful as a conceptual reference, to give some concreteness to what Hegel is talking about, but never to reduce it completely to discourse or even think that they are near identical. But we should note that this comparison isn't all unfounded as regards the inner essence of the projects of the two thinkers. What we're saying here indeed takes advantage of Spirit and discourse's profound commonality in being elaborations of the Greek concept of logos (in the sense of legein, gathering together, as well in the sense that logos gives noein, intuition), and in that sense this does not remain a mere exercise for thinking Hegel concretely.