Believe it or not I can actually see Zach Galifianikas as Ignatius Reilly not so much because of the obvious typecasting but because of what NOLADef's Shay Sokol hints at in this paragraph.
Ignatius J. Reilly once mused, “Apparently I lack some particular perversion which today’s employer is seeking.” Zach Galifianakis – the comedian who smoked a joint on television – might be uttering those lines to himself this weekSokol is actually trying to make a slightly different point with that quote but it hits very near to the heart of Confederacy which I've always thought of as a subversive book. Or at least, I think it succeeds because it captures that essentially subversive something about New Orleanians that makes so many of us incompatible with "the particular perversions" of regimented employment in Ignatius' or any other day. If you've seen Galifianakis' standup act, you get the impression that he's just smart enough to strike the right tone.
On the whole, though, I still don't expect Hollywood to get this right no matter who they put in the cast. It will be too tempting and too easy to turn Confederacy into a gross-out slapstick like the American Pie franchise rather than stay true to the Simpsonsesque satire it really is. Anyway, as we all know by now, the odds are against the movie ever getting made which is just fine with me.