When I get the new MBP, I will be also investing in a external mouse and keyboard, just wondering weather I should the wireless keyboard and mouse from Mac, or the ones with cords..I heard, the ones with cords, are always better more latency etc..
I agree with scaredpoet that the previous generation of wireless Apple keyboard were the best ones. I use one with my MBP, and I do not notice any difference in keystroke response/delay as compared to the wired one.
If you can get the previous version, I would highly recommend it.
The problem with the USB ports on the wired keyboards is that they aren't powered, so things like USB flash drives and other items that depend on power from the USB port will not work.
If you can find the Apple Wireless Pro Keyboard (the full-sized one before the aluminum version came out) then I highly recommend getting it. I have one and use it a wireless keyboard for a Mac mini, and love it.
And for what it does, I like the wireless mighty mouse, but to each his own. I'd say get it if you like the wired version. My only complaint with the wireless version (I have two) is that there seems to me more play between the top and bottom halves of the mouse, and so the tactile feedback of clicking the mouse isn't quite the same as in the wired version.
I would go for the corded keyboard because it has two usb ports on it. The wireless keyboard is just too small for a normal keyboard to me. IMO I would go for another brand for a mouse because of better features, price and variety.