It adds an external media card slot, OS 4.3 (which will be available on the 8100 in a few months anyhow), video recording, a 2MP camera (a la Curve), more durability and better build, wi-fi capabilities, etc. If you aren't interested in any of that, then there's no real reason to upgrade ...just wait it out until the 3G BB a few months after.

We'll see the 8120 stateside in Q1.