In 2002 we got the absolutely beautiful YA fantasy book Abarat, by Clive Barker. In 2004 he published what was supposed to be book 2 of 5 in the series. In 2011 we finally got book 3 of 5.

His website still says he's working on books 4 and 5 and there's synopsis and artwork, but no eta and it seems like the website hasn't been updated in ages. So I just don't think I'll ever get to experience the end of one of my all time favorite series (that I still recommend whenever applicable, the first book is just too good).