One thing that you may well be tempted to give only passing mention to is the new Book module.
Now the Web module has usually been given fairly short shrift, and I think with good reason. The output, whilst perfectly respectable is nevertheless very basic, and a decent wordpress skin can knock the socks off of what LR will easily produce. Also Adobe have of course some very powerful web tools and products.
By contrast I think Blurb is pretty much at the top of the heap of the major on-demand book producers. Photo books have a long and distinguished history and I am incredibly excited over the Book module. I would love for you guys to actually go into some real depth here. It will likely be almost as important as the Print module for some of us.