The new model will be a bit thinner and have a scroll wheel a la the mini (the four buttons are gone). Rumor has it there will also be a price drop. (I don't know if you guys have noticed, but there are already some retailers dropping the price of the 3G models - in the past, I heard that Apple wouldn't even let them put it on sale).
The Newsweek article is up, but it looks like their servers can't handle the load.
Seems like a nice incremental upgrade, but probably not enough for most people to upgrade. Right now there are two reasons I would consider upgrading: A full-size model with WiFi / Bluetooth and a color screen or a 10GB mini. After seeing the mini (my girlfriend and a good friend both have one), I'm very impressed (I didn't think I would be). It really is a noticeable difference in your pocket, and a very slick device.