There is another Asus X99 board floating around which wasn't mentioned at launch and that is the Asus X99-S. Looking at it visually they both look identical, but there are some differences, and the differences are. (All info taken from their manuals)
Asus X99-S
Memory: 64GB max DDR4 up to 3,200 o.c.
1x Intel Gigabit Lan (I218-V)
No wifi or bluetooth
Back has 8x USB 3.0 and 2x USB 2.0
Comes with 3x SATA 6Gb/s cables
A SLI bridge
M.2 Bracket
Asus X99 Deluxe
Memory: 64GB max DDR4 up to 2,800 o.c.
2x Intel Gigabit lan (I218-V and I211-AT)
Wireless AC up to 1300Mbits/s + Bluetooth 4.0
Back has 10x USB 3.0 and 2x USB 2.0
Comes with 8x SATA 6Gb/s cables
1x 2-3 way SLI bridge
1x WiFi+BT Antenna module
1x M.2 x4 PCIe x4 card (optional)
1x M.2 x4 bracket
1x Fan Extension hub (optional)
1x Fan Extension hub cable (optional)
1x Thermistor cable
http://www.amazon.co.uk/X99-S-Motherboard-Express-Channel-Socket/dp/B00N1XQ4F8
http://www.overclockers.co.uk/showproduct.php?prodid=BU-022-OG&groupid=2833&catid=2512&subcat=2513