The aim of the site is to make finding apps easier, something that has long frustrated Android users. Before today, Android users have had to find and download apps solely via their mobile devices, an experience that pales compared to the browsing and sharing abilities offered by iTunes and its associated website.
The Android Market website makes finding apps much simpler: there are categories down the left hand side, separate tabs for paid and free apps, as well as a search features, something that was oddly missing from the search engine giant's previous app marketplace. If you purchase an app via the website, you can send it directly to your phone.
The market should also link to your Google account so you can log in and see all the apps you've purchased and downloaded (but this feature, along with several others, returns an "invalid request" error message).
Launch-related bugs aside, the new website should vastly improve the app browsing and buying experience for Android users.