1. A 4G, sideways-widescreen iPod nano
A fairly obvious one, given the increasing legitimacy of this theory. It all started with Digg founder Kevin Rose's purportedly leaked photo, which eventually gained more credibility with photos of cases for this skinner version of the nano at the IFA 2008 trade show. A fan's mock-up of this rumored nano makes it appear more legit, too.

2. A sideways-widescreen iPod classic
This is what my gut tells me, and Macworld's Chris Breen thinks so, too: Apple isn't going to let the nano steal the spotlight from its precious big-kahuna iPod that got all of this started. Thus, if the nano it going to be flipped sideways for widescreen viewing, you can expect the iPod classic to have the same form factor, only with a slightly larger screen and a substantially larger hard drive. Since the current iPod classics are 80GB and 160GB, you can expect the capacities to expand to somewhere between 120 and 220GB (rough estimate).

3. Minor revisions to the iPod touch and iPod shuffle
It's been about seven months since Apple refreshed the iPod touch, meaning the current line is about to reach the end of its life cycle. Following the footsteps of the iPhone, we can expect the iPod touch to get a tad skinnier in depth, but for the most part it should be the same -- since Apple wouldn't want the touch cannibalizing iPhone sales.

As for the shuffle, Apple could make these things smaller, but that'd probably just be impractical and inconvenient for the user -- and the world leader in industrial design isn't going to mess this up. Why fix something that isn't broken?

4. And a software update for the iPhone that will solve all of its 3G network problems!

Just kidding - wishful thinking. But on a more realistic note, we'll likely see an update that at least fixes that major security flaw discovered recently.

Gadget Lab's looking forward to this event -- since all the craze about the iPhone 3G is starting to simmer down. Stay tuned; we'll have a full report of the event come Sept. 9.

(Photo credit: key1/Flickr, Apple)