Will the new charger design work for a Penryn MacBook?
I can't tell if the actual connection point of the cord to the computer is shaped just like my magsafe on my Penryn Core 2 Duo MacBook.
The new charger design with the aluminum end will work with my older white MacBook, right?
Yes it does, I've used the new charger with my Core 2 Duo and I have to say it looks stunning. If I felt like wasting the cash I'd buy one of those to use instead of my plastic one. The MagSafe connector is an Apple standard and universal throughout their products, the actual connector has not changed, it's just aesthetics.
The newer cords come in either a 45w, 60w, or 85w design.
45w = MacBook Air
60w = MacBook/13" MacBook Pro/15" MacBook Pro (2009 revision WITHOUT 9600m GT)
85w = 15" and 17" MacBook Pro
Either a 60w or 85w will work fine with your Penryn MacBook
Universally, the MagSafe connectors are the same... but if you choose to buy one, make sure it's at least a 60w adapter.