Nokia has released a free OS2008 upgrade for its N800 Internet Tablet. Weighing in at 134MB, the upgrade will give N800 users an improved user interface, improved finger navigation, and improved performance among other new features.
A comparison at the package level between the latest version OS2007 and the new OS2008 is available if you want to see all the details of the changes.
An update (with minor optimizations and bug fixes) to this latest version (v. 2007.50-2) is also available for the N810.