According to a product listing at Rakuten and VGMdb, Capcom intends to release a 12-disc Rockman X soundtrack collection tentatively titled "Rockman X Sound BOX." It's due in Japan on December 18th, priced at 12,600 Yen (roughly $127.32 US). It would appear Devil May Cry is getting the "sound BOX" treatment, too. That one's a 4-disc set.
No images or track listings at the moment. More news at it comes.