Nokia has just started rolling out the v40 firmware for the Nokia 5800 via the Nokia Software Updater. The chief changes are the implementation of partial kinetic scrolling to the device and a reworked homescreen to match the new 5530. Other changes include auto-switching to the on screen QWERTY keyboard when you turn the device and a few optimizations to the tap/double-tap selection process and the addition of Ovi Contacts.
The update is now available over the air as yet and may not even show up on the NSU across all regions, as always patience is the key. This update is a definite must do, although if you care about ‘hacking’, it appears that has been blocked with this release.
The Nokia 5800 features user-data-preservation (UDP) so you will not loose any data when you update, but backing up the device is still a good idea.