My take on this is similar to Justin's (if I understand him correctly) - something of a halfway between the full acceptance of say, someone like the late Fr.John Romanides, and the view in the other direction which recognizes only 7 Ecumenical Councils.
I think the 8th and 9th Councils meet all of the criteria of the previous Councils. They were definately Imperial Councils, becoming part of "canon law" (which in it's original understanding did not simply have ecclessiastical consequences, but also secular, legal ones.) They definately speak the Church's mind on the subjects they touch upon.
What is problematic is their acceptance, latter, clear, re-affirmation as being "ecumenical." That they are not ambiguously recognized as such, in my view, is purely a result of historical circumstances - the fall of Constantinople, and most directly, the machinations of the Papists (both before, and after the fall of Constantinople - for example, meddling with the contents of canonical works printed in Italy for use amongst the Orthodox). This sneaky maneuvering by the Latins also includes the self inflicted injuries caused by later Russian "westernizations", which often accomodated the absorption (almost by osmosis) of incorrect Latin assumptions (a key one being, the last Ecumenical Council which the Orthodox world can claim, is the one they shared with the Patriarchal See of Old Rome.)
Thus, I think they ought to be recognized as being on-par with the previous seven, and sincerely believe that the only thing that has prevented this were alien influences and circumstances beyond the control of Orthodox peoples.
Perhaps one of the pivotal acts of these latter days, will be when the Church of Christ gathers to Oecumenically repudiate the heresy of Ecumenism - I wouldn't doubt that in said context, these Councils will gain the recognition ("officially") which they lack now, since their contents pertain directly to some of the errors of the ecumenists (in particular, these council's unambiguous condemnation of Papism, which at this point many ecumenists pretend is non-existant; that is to say, that there are no conciliar condemnations of Papism, in the way that their are of the Monophysites, Arians, etc.)
Seraphim