I'm definitely excited, Smashwords has done lots of great work on this, and I will be thrilled to see my books show up on the iBooks store, especially if it's at launch (which they hope will happen, but we shall keep our fingers crossed and see!).
And I like the clause requiring lower pricing than printed books, that just makes sense. Amazon has a similar clause tied to its 70% royalty change coming in July, so hopefully it will become a clear trend.
EDIT: Both of my novels went live in the iBook store on launch day!

Unfortunately, the categories in the iBook store are a bit lacking, so you generally have to search by author or title to find a specific book you want.