I've been saying this for years -- two or three slow machines are more efficient than one fast machine. Often cheaper too. The pursuit of "the latest/fastest/latest/bestest" is a fruitless one: you'll never keep up with the changes in technology. But quality purchases won't disappoint. I still use a 1999 Mac for email and such. My (now ancient) 2004 dual-processor Mac will one day just be a file server -- and a very good one at that. These days, most of my work is done with a current dual-core PC laptop (for Photoshop work, about as fast as my old dual processor Mac). I imagine a future where all the power is distributed across my network (e.g. iTunes server, file server, RIP, etc) and I interface with everything with a laptop and/or mobile phone.
Actually it's much easier havinf discrete machines for different tasks, much better than overloading one or having a problem with a bit of software that takes out the whole machine!
