I find bookjetty very useful to create a "shopping list" before I to the library to pick up books. I'm wondering whether it would be useful to have a "shopping list" category (perhaps by another name) to separate this temporary list of books you have a slight temporary interest in from those you want others in your social network to see you have a definite interest in reading. The downside is it may complicate the interface and that is one the best attributes of bookjetty IMHO.
For books that I already bought but have not yet read, it is actually difficult to put them here. I end up adding them in the Wanted section when in truth, it is something I already have but just haven't gotten around to reading. I like the addition of Dropped. But I think you should still add a new category that will show which books one has but has not yet read.