Hey bozo, this is a Core2Duo Mac Mini, so that's fightin' talk around here.
That said, this is an early-2009 vintage and was showing its age and I would have replaced it this year with the big shiny, but I snuck in 8 gigs of memory and a SSD and it really does fly now (the irony that it feels a lot faster than the brand new Dell Win7 i5 laptop that also sits on my desk is not lost on me). Where it doesn't fly is processor intensive stuff, so transcoding movies for my iPad is a task for the patient.
If it's cheap and your needs are simple dabbling and media playback, the Core2Duo would be OK, but bear in mind it's the trailing edge of what is acceptable and I'd not be surprised if it fails to meet the spec for the next version of Mac OSX (if you want to use what the kids are using). I have a non-Duo Intel Mac Mini used as a media centre. It's mostly fine, but struggles a bit with HD (that model had poor, even for its time, integrated graphics). The plan, before I inadvertently extended its life, was to move this machine downstairs and retire that one. It'll probably happen at some point.
If you want any degree of future-proofing, then the Core i5 is the way to go. Be warned though, Macs are addictive. Once your cult membership dues clear, there's no going back.
