The shingles are HardieShingle Straight Edge Notched Panels, which are not actually individual shingles at all, but are 4' long fiber cement panels which are notched to look like 6", 8", and 12" wide shingles with a 7" high exposure. They have a subtle vertical wood grain that makes them look more like their cedar brethren.
For those of you who haven't heard of James Hardie products, they are basically wood look-alikes made of fiber cement. They make lap siding, vertical siding, shingles, exterior trim, and soffit boards. They are also well known for their HardieBacker tile backer board. This is my first home remodel using the siding products, but so far so good!
The pros are easy: No trees were harmed in the making of this siding. Won't curl, crack, or split like wood. HardieShingles have 30 year warranty, ColorPlus finish has a 15 year warranty, and the integral color means you don't have to pay for paint. Fiber cement is non-combustible so the whole house is much more fire resistant, termites are not interested, nor are fungi so dry rot is not an issue. The cost is close to cedar shingles, and when you take into account the savings on paint, it's a great value.
The cons: The dust is ridiculously toxic, respirators and vacuum hook-ups are a must to avoid lung damage when cutting. Cutting requires a specialized (read: expensive) blade. Cedar brown shingle homes have a warmth and architectural familiarity that these can't duplicate -- the notches are just too perfect, the panels too flat. All in all though, I think that's a small price to pay to have siding that's virtually indestructible, green, and low maintenance.