I'm going to purchase a new thinkpad in the near future. I'm not sure if I should buy a T520 or a T530.. I don't mind getting a different style keyboard from the T530, but i'll be taking most upgraded parts out of my T420 and using it on the T530/T520. The T530's battery is different, but is the ram compatible? I'd buy the best processor/panel/graphics card available so the T530 has better specs.. Do you guys have any suggestions/ advice?

I think the battery is compatible too.

From first glances and early reviews, it seems that if you don't mind the new keyboard layout, then the Ivy Bridge machines are a good buy.

All T530's have USB 3.0 ports, T520's have only USB 2.0. Huge difference, especially when backing up data.

No; it's a downgrade for backing up data since it lacks eSata