The best way to describe affinity is to say that it will be a front-end to all the information on your desktop, imagine it as 'Planet' to different feeds on your desktop, such as beagle/tracker, recent documents, bookmarks, tags, contacts, etc. It can be called from either a key-stroke or from the gnome-panel. Some features :
* It has search-as-you-type.
* Actions (like typing "www.google.com" will present you with an option to open it).
* Written in C, its extremely fast, even on a old system.







This information was taken from this Blog Post.
Affinity's websites in Google Code.