Mine is scheduled for delivery tomorrow too... I'm so ready to get it hooked up at the office!
The SP3 dock is NOT a USB hub. I'm not even going to go into all the reasons as to why it's not, as you're free to do your own research, but to say it's anything like a USB hub is just an outright lie.
Agreed, it is so much more. I spent a semester of school coming home each night and hooking up my SP1 to a usb hub, my monitors and speakers, and plugging it in with its power cable. Granted, I only spent about 45 dollars for the usb/ethernet hub and dvi cable, but the inconvenience of daily hooking and unhooking cables, hooking up the power cable and then having to disconnect it all to go back into my backpack, really got to be a pain and hindered me from unhooking once hooked up for casual use. After using the cheaper alternative, I am very excited to have the opportunity to use the new dock.
As I'm writing this I DO realize how petty having to hook/unhook cables may be for some and in that case I recommend you go with the cheaper alternative as I have tried. This was definitely a WANT and not a NEED, but am looking forward to the ease of it very much.