Also, since I hadn't seen it mentioned too many other places, the Arts & Artifacts Limited Edition for the US (not the Japanese version) has been revealed and is pre-orderable at least on Amazon right now.
The price is a bit steep at $79.99 (msrp). It appears to have a slipcover that "unsheathes" the Master Sword when removed. No mention of additional content beyond the cover though. Run size is "limited" to 10,000 copies (pretty big run for a limited book though, even by Zelda standards).
Amazon.com - Limited Edition
Amazon.com - Regular Hardcover Edition