I am pleased to announce that my co-author Eric Carter has made significant updates to our VSTO book. (Though I notice with chagrin that one of the changes is that the title is much shorter than it ought to be.) It is not yet available in bookstores but will be soon.
The new parts of the book (which I did no work on at all, this one is Carter's baby!) cover the 3.0 version of VSTO in great detail; if you're looking for the definitive work on the subject, this is it.
See Eric Carter's blog for more details to come.