I'm not sure what you mean exactly but the S in the iPhone 3GS stood for speed so I'd assume the S in a potential 4S represents the newer A5 dual core processor and other spec bumps.
Apple uses code and leeks to confuse people so during launch devices will surprise public. We will get iPhone 5 because ios5. Think about it. If my statement ain't true next year iOS 6 will be on an iPhone 5. Don't make sence. So in conclusion , we will get iPhone 5 and a iPod touch 3G or even 4g
Lets go with history
iPhone (2G/EDGE) iOS 1
iPhone 3G iOS 2
iPhone 3GS iOS 3
iPhone 4 iOS 4
iPhone 4S iOS 5
The OS is not exactly congruent with the name of the phone. It's more of a generation thing. So don't say apple is trying to confuse, because they aren't. And yes, you will possibly be correct, iPhone 5 will be iOS 6. iPod touch 3G? I highly doubt it, they have to keep the kiddies happy and parents happy, don't want to sign the kid up for a contract on a device they may throw down for the next shiny toy in 6 months. iPad is the way to go with that. And 4G, may not even be in the next gen iPhone, I say 2013 before we see it. When the real 4G comes out and it becomes an industry standard. iPhone (2G) didn't have 3G at firs, so yeah.. I think an iPhone (4G) is a long way off...
I don't think we'll ever see an iPod touch 3G (but I'd love to be wrong). Mostly because of space issues with the 3G antenna, carrier anxiety over unlocked / out-of-contract devices on their networks, and overall prices of 3G devices (e.g., you can get an iPod touch for WAY cheaper than an iPhone, which has a 3G antenna).
that really is a bad representation for what the 4S is. It is a sound and safe decision for apple to make. Plus, who would want an iPod 3G, which I assume you mean iPod Touch 3g, because you weren't specific. They already have an iPad 3G, why get a smaller screen?
by now i'm pretty sure it's okay to assume it's the iPhone 4Siri.