Not sure why, but I just went through what they transferred. Don't know if this will be of interest to anyone, but here we go...
My FW account shows 440 books. Of those they haven't transferred 10, but of those 10, two were freebies used for testing DRM and three are not really missing as I had them in my Nook account already from past freebie offers so I'm assuming that's why they didn't transfer them (again). So I'm counting it as there really being 5 missing, which is pretty darn good. Of those 5 I'd really like to see two of them show up, the other 3 were freebies I'd picked up for a friend and couldn't care less about. One of the missing is the Lord of the Rings omnibus which it looks like they transferred just the Two Towers for by mistake. There is also a book called How Few Remain by Harry Turtledove which isn't listed at FW and may have been mistakenly transferred for one of my missing books, like Two Towers was.
There are 30 books with missing covers 19 of which were freebies from back when they did freebies for some of the Hugo (or some other award) nominations and didn't have cover at FW either IIRC. Of the other 11, 9 of them are duplicate books and the other copy has a cover (kind of odd) and the other 2 are books from Big Six pubs.