Originally Answered: Should I get the iPhone 4S now or wait on the iPhone 5 to be released?
1. It's not going to be called the iPhone 5. The 4s is already the 5th generation iPhone.
2. EDIT: To further clear up confusion: there is no confirmed release date. There aren't even good sources claiming a June release. While it's very likely, there is no factual basis
Anyways back to your question:
1. The 6th generation iPhone (I personally think it'll just be called just the iPhone, don't think it's relevant why) will be released either in June or October 2012. A June release is pretty logical but there is no *real* information regarding it; the 4s was just released
Now, the 6th gen iPhone will probably be a huge update: new form factor, possibly larger screen, and maybe even a quad core processor (and yes, the technology for mobile quad core processors will be out next year, but Apple doesn't just cram specs for the sake of it).
There are couple reasons: firstly the 3g/3gs -> 4/4s thing (minor upgrade, major upgrade cycle). Secondly, There is a lot of technology like NFC (near field communications) that are kinda in "their birth". Apple makes their products so they "just work", which is why they didn't include things like LTE in the 4s (uses too much battery life, not very much coverage anyways).
So, it probably sounds like the 6th gen iPhone will be a killer, which it probably will, but it's really up to you. It won't be coming out anytime soon, and the 4s is a great phone. If you think about it, so many of future features aren't really "necessary" - I mean, we've been living without them since the beginning of time anyways. I can't tell you exactly what to do, since it just depends on personal preference. My 3gs just broke and I'm waiting for the 6th gen.