I have the Microsoft Natural Ergonomic Keyboard 4000 bought because I write a lot (about 5,000-7,000 words a day). The ergonomic shape is a real relief when you sit properly and always constantly on the position of the hands watching (what you actually should but after 8 hours of work sometimes subsides). Unfortunately, the quality of this product to be desired. After only a few weeks to several letters had completely rubbed off. Today, 6 months later, the S, D, F, C, V, B, M. and, keys no longer readable. The spacebar is also worn visibly. Although I do not look at the keys to type to Microsoft but I would have expected a little more. In particular, at the price. The attack is very hard; especially when the space bar was the beginning extremely uncomfortable (blisters on the thumb - really!). This will lessen over time. But I like prefer a slightly softer attack with an audible "click", as in the good old IBM keyboards that unfortunately does not look on the modern desk today very chic when they still found.
In addition, I would have my Logitech MX Revolution mouse software for after installing IntelliPoint install again as MS probably can not imagine that you can work with another mouse as their own.
The special keys work pretty well. Some are programmable. Calculator, favorite applications and web pages has to reach immediately, with a push of a button. However, the push-button would be better than the scroll key, because one can zoom with your mouse people are looking for relief for your hands / joints, rather scroll with the keyboard than with the mouse. The scroll with the wheel should be a fixed or programmable function, and not a "hack".
Conclusion: Good idea, only less well implemented.