This is turning out to be a good year for new books related to costume. The people who published The Tudor Tailor just published a new book, The King's Servants. I just received my copy a week ago. Though it's no bigger than one of the Osprey military books (it's only 48 pages), it is packed with detailed information (and excellent illustrations) concerning men's costume of a particular period--1485-1511. The information is derived from period wardrobe accounts and makes a fascinating read.
Here's another book coming out this year that I'd like to buy: Marion Campbell, Medieval Jewellery: In Europe 1100-1500. V & A Publishing (November 1, 2009). ISBN-10: 185177582X. Judging by the product description that appears on Amazon, it will feature pictures of jewelry items in the V&A's collection. Fortunately for me, Amazon is selling the book for under $20 USD.
Finally, (speaking of Osprey military books, Timothy Dawson is publishing another book on Byzantine military life (and costume!) this year. Having covered (Middle) Byzantine infantrymen last year, he is publishing another Osprey book on (Middle) Byzantine cavalrymen this summer.
Clearly, it's going to be work, saving up for NESAT X. :-)