I'm a big fan of Microsoft's Sculpt Ergonomic Keyboard. Marco Arment's thorough review convinced me to fork over around 80 bucks for the mouse-included Desktop bundle (on sale) several months ago; you can't buy the keyboard standalone. It made an immediate difference in keeping my hands comfortable and ache-free when working from home and typing away. Today, Microsoft introduced a successor to the three-year-old Sculpt model: the Surface Ergonomic Keyboard. It's available to pre-order now for $129. That's just for the keyboard this time; they're not forcing a mouse on you. It's far from cheap, but should easily be worth the cost if typing at a desk is something you spend doing for multiple hours every day.
There are a few differences between the Surface and Sculpt versions. The most important change is in the way they connect. Using the Sculpt required wasting a USB port and plugging in a dongle, but the Surface Ergonomic Keyboard uses Bluetooth. That's good! The Bluetooth alone might convince me to upgrade. A number pad is now included in the main layout, making the keyboard's footprint larger than before. With the Sculpt, Microsoft included a separate, also-wireless number pad that you could either position next to the keyboard and use — or toss in a drawer somewhere. Since the Ergonomic Keyboard isn't really something you'll be traveling with, it's probably the right choice to just add it permanently. Plus, that added space allows for a proper Fn button instead of the toggle on the Sculpt. The Surface Ergonomic is still powered by 2 AAA batteries, but don't worry about having to replace them often; I can't think of the last time I did with the Sculpt. Microsoft claims the Surface version can last for up to 12 months on a single pair thanks to Bluetooth LE and smart power management.
The look has also changed some; it's now gray, the most obvious distinction, and Microsoft says the palm rest is covered with mélange Alcantara fabric, the same soft material that's used in the Surface Pro 4 type cover. The Sculpt Keyboard uses a cushioned, soft-touch palm rest, so I'm rather curious about how different this keyboard will feel because of the switch. One other downside: the Sculpt keyboard came with a piece of plastic that magnetically latched onto the bottom to raise the palm rest a little higher on your desk, but Microsoft seems to have ditched that option this time.