why do you need 8 cores?
The average user doesn't need an 8 core machine, but since they went to intel, everyone is saying how slow photoshop is. (Because of rosetta. Its also one of the main apps used on macs) So it kinda makes sense. Just as Adobe releases their first true intel version of photoshop, apple releases a supercomputer for that market. They go from blah-slow, to SWEET-Fast.
Plus as a programmer I wouldn't mind on for a home server. Maybe look into virtualization and have more then one operating system running at once. ohhh the possiblities. As well as, if you bought that machine today, 5 years from now, it might not be bleeding edge, but it would probably still be considered 'reasonably fast'.
I haven't really looked into it but, can you get VM-Ware running on intel macs? Can you run windows, OS X, and linux at the same time? And NO I don't mean doing that using bootcamp.