There are a couple of other relatively minor, but significant changes in Windows 8 that may make it worth an upgrade for Windows 7 users. Windows 8 has a cloud focus to it which might be a tempting feature. Microsoft stores all your settings and customisations in the cloud so whenever you log on to a Windows 8 machine you will have it looking and working your way.
Other elements of the cloud system include pulling your email from Gmail, for example, and viewing all your photos from Facebook. And each Windows 8 device comes with a ready-enabled SkyDrive account.
In terms of security, as well as the additional peace of mind that downloading apps from a curated Windows Store brings, Windows 8 features a lock screen which allows you use a picture password. This means you can affix a photo to the lock screen, and replace your password with a gesture traced out over the photo. Because of the additional complexity this adds in over a traditional alphanumerical password, it ought to be more secure.
Staying with the theme of security, Windows 8 is the first flavour of Windows that comes with antivirus baked in, in the form of Microsoft Security Essentials, which sits alongside the software firewall in Security Center. You could justifiably save yourself a few quid by not bothering to buy security software (although standalone security vendors will have a thing or two to say about this). There's also an all new Task Manager, offering two different ways to view information: one simple, one more complex.