This is by far the best keyboard that I have ever used.
I purchased mine over 18 months ago in January 2010, it still functions as if brand new, and I haven't had to change the batteries once, contrary to the popular belief that wireless keyboards have poor battery life.
Whilst being aesthetically pleasing, it is also extremely comfortable to use, and contrary to some of the other reviewers comments, I find it has a very strong wireless connection of which I have experienced no problems with. It is one of the few hardware products I have purchased that I have no complaints about whatsoever.
Perhaps the only minor drawback is the fact that there are no lights on the keyboard to inform the user of whether they have Caps Lock, Num Lock, or Scroll Lock activated, however, the 'Microsoft Intellitype' software that comes with the keyboard (and is also downloadable for this particular model from the Microsoft website) informs you when you have activated these.
Overall, the keyboard receives and deserves the full five stars, I am extremely happy with my purchase over 18 months later, and I'm confident I will still be using this keyboard for many years to come.