Looking at the machine and wallpaper, it appears to be running OS X 10.6 Snow Leopard, while 10.7 Lion is the current release. Head to the Apple menu and choose About this Mac, and see if it has a Core Duo or a Core 2 Duo processor. If it's a Core Duo, 10.6 is the end of the road. If it says Core 2, it can go to 10.7.

If you do go that route (which is the only way to see the initial iCloud desktop integration), I'd recommend maxing out the RAM in that machine first, which is 4GB I believe. RAM and the hard drive is accessible when you remove the battery, help for that is here: http://support.apple.com/kb/HT1651

And as far as the Zune HD, not going to knock it. Especially when it's fully supported on your Mac there, by following this link into the App Store.
http://itunes.apple.com/us/app/windows-phone-7-connector/id415571499?mt=12