Keyboard
The Microsoft Arc Keyboard is unique in its styling and configuration. The name arc comes from the keyboards arc shape, curing up in the center which has 2 benefits, the first is that it’s supposed to match the natural configuration of the human hands, as well as being able to rest comfortably on your knees if used in a home entertainment scenario.
Typing on the keyboard does take some time to adjust to, especially after having the muscle memory established on flat, laptop-style keyboards. Over the course of a few days your hands adjust and typing is fine. Note: I am a touch typist, if your a hunt and peck style typist, this really won’t be an issue. Part of the adjustment comes from the increased distance between keys. The Arc keyboard has chicklet style keys, similar to that of recent apple products, the difference being that the keys are higher. This means the gap between keys is deep, this can prevent you from free flowing from one key to another.
After first opening the box, you’ll notice this keyboard is small and light. Microsoft have had to make some serious sacrifices to reach this form factor. There’s no num pad which isn’t uncommon in laptops, but is rare for a desktop keyboard. There’s also a condensed navigation section, with the up, down, left right keys being condensed into a single 4-way key. This takes a bit of getting used to.
Looking to the top of the keyboard, there left hand side contains the standard F1-F6 keys, but to access F7-F12, you’ll need to hold the function key. Move across you’ll find Home(/Printscreen), End, Page up, Page down, then media controls, which are incredibly responsive, then top right is a decent sized Delete key. Great for correcting mistakes without looking. 
Mouse
Designed for portability the Microsoft Arc Mouse folds in half for easier travel. In it’s folded mode, it’d easily fit in your pocket, but before taking your mouse on the road, just snap the USB Bluetooth module in the underside of the mouse. After using the mouse for the best part of a week, I’d have to say the arc is simply too high to be comfortable and the back button is way to far forward to be accessible. Overall the mouse works great, it’s super sensitive which is great when gaming, but even in general desktop use. I run 2 monitors running 1920×1200 resolution, so moving from one side to the other can require quite a lot of physical movement with some mice. With a sensitive mouse like this, I actually had to turn the mouse speed down and can now move across the 3840 pixels with a slight move of the wrist.
Connectivity
What was surprising to me is that the keyboard and mouse need their own separate USB Bluetooth module, taking up 2 of your USB ports. Sure a wired solution would have the same requirement, however there are other Microsoft keyboard and mouse solutions that have a single USB dongle. Admittedly the Arc system is easier, just plug in and go, rather than have to sync each device.
Gallery
Device Stage
If your not familiar with it, Windows 7 comes with a new feature called Device Stage. Designed to be an attractive, functional interface into new devices connected to your system. Unfortunately there’s very few devices that currently support Device Stage. The Microsoft Arc Keyboard and Mouse does support Device Stage, a welcome addition, and naturally you’d expect the company to support it’s own hardware. Lets hope more hardware manufacturers adopt Device Stage in the near future.
Update
After testing the Arc keyboard with the Xbox 360 I found a weird glitch. Whilst the keyboard works great in the standard Xbox 360 interface, it fails in Media Center. Strangely only the left and right functions work, up and down does nothing. This is possibly due to the keyboard combining the 4 arrow keys into a single key.
Disclaimer
After posting on twitter that my Microsoft Explorer 3.0 mouse had died, I received an email from Microsoft. They offered to replace the mouse and after further discussions sent me through a Microsoft Arc and Keyboard.
More info @ Microsoft Hardware
