yeah its symmetric multiprocessing. therefore you get the equivalent of two 2Ghz machines working on the same code at the same time. Dual processors dont add, it pretty much is the work is distributed to less-busy processors. PCs do it this way as well. the programs that take advantage of dual processors are multi-threaded so the program can utilize the processors as its written. Most programs though arent multi-threaded so, they will run on processor one, while the other sits either doing work for the operating system or waiting for instructions, unless the operating system has the ability to assign processes to certain processors where then the os keeps both processors busy automatically. Its late, and this probably makes very little sense.
Tech-TV hasnt had their hands on one yet to my knowledge. The keynote presentation was very very convincing when it comes to showing the comparision of the two systems. I am not sure if they are still showing the keynote, but the photoshop comparison was very convincing in the keynote. as it took the pc a couple of minutes to do what the g5 did in less than a minute and a half.