Well although I have a dvd on Mental Ray already, I think its something thats dearly needed on this site, as a lot of newbs are using it incorrectly, even more experienced guys are, so something in this area to break the MR mythos and perhaps lighting and rendering in general from basics to advanced.

Perhaps more to do with shader networks and some of the utility nodes, along with the basics of shading materials, as I see alot of newbs again asking about how to create a bump map.

Also something to do with Camera mapping techniques for 'Matte Painting' would be cool (calling Pure Morning) as its something Im trying to get into more and is a time saver in Production.

And perhaps something on hair and fur alone, without modelling included just to concentrate on that alone would be sufficient.

And finally a biiiiiig wish...how about the new kid himself...ZBrush, and using it with the Maya workflow in general

Cheers
Jay