I assume by now you've heard that Apple is switching over to Intel next year, and that the PowerPC development will stop after that. As a result, demand for PowerMacs is expected to drop and the speeds will likely never exceed 3GHZ. I am going to start running Linux side-by-side with MacOS because I expect I will eventually switch over to it in the 1-2 year time frame. One of the main reasons Apple is switching to Intel is because the Intel chips have DRM (digital rights management) built in to the hardware. This will make it theoretically impossible for hackers to bypass it. So, no more "fair use" or anything like that. You will only be able to do with your movies, music, etc. what the distribution companies (MPAA, RIAA, etc.) want you to be able to do. You will not have total control over your computer -- they will.