Reasons to not try Windows 7

• The beta of Windows 7 will be available to the first 2.5 million people who download it on Jan. So don't get your hopes up too much.
  

• The Windows 7 will expire in August. So be prepared to lose data. Because you will have to go back to the older version of Windows after the expiration of Windows 7 beta.
  

• And read this:

As much as the Windows 7 Beta completely rocks, part of the beta process is discovering bugs and reporting those bugs. Some of those bugs  could possibly lead to data loss. I tend to be a risk-taker myself and have gone all-out with the Windows 7 Beta by putting it on almost all my PCs both at work and at home, but not everyone should do this.

• You need to find drivers for your all hardware. It is a highly possibility to find all the drivers because it is a vista based OS, however there are still some risk to have driver compatibility problems .

• Also, there might be compatibility problems with some software as well.
  

If you just want to install the Windows 7 for the visual changes, I would recommend you to check out Windows 7 videos. (There are plenty at Youtube ). Because, I don't really think it worth for the trouble that you will have. But still the last decision is yours. If you decide to try it good luck, and let us know how it goes ;)