Various websites have taken a look at Microsoft's Windows 7 Preview and published their first impressions.
ARS Technica has some coverage over here and talks about the various changes Microsoft has made to the user interface of Windows 7:
These UI changes represent a brave move by the company. The new UI takes the concepts that Windows users have been using for the last 13 years and extends them in new and exciting ways. Windows 7 may not change much under the hood, but the extent of these interface changes makes it clear that this is very much a major release.
Some more coverage can be found at Neowin, they say it's a great improvement over Vista:
My first impression of Windows 7 is that it's a great improvement on Vista. It has improved performance, a neat boot screen that fires up devices quicker than before and the improved taskbar and windows management features will help when switching between various applications. Throughout the rest of PDC Microsoft will be unveiling more information about the Windows 7 desktop improvements. We'll be there so keep an eye out on our PDC section.