All the talk I am seeing on twitter about the iOS app makes me drool, but having a rather old iPod, I shouldn't get my hopes too high and first ask: will it work on all iOS versions, what is the lower version required?

iOS 5 is the minimum version required...

For the beta, iOS 5 I think. They've mentioned elsewhere that the final version would be iOS 4.3, I think?

It was initially 4.3, but now it's iOS 5 only...

Yikes! That kinda blows since I have an iPod 2G.
I've been looking around for jailbreaking to upgrade to iOS 5, whited00r looks like a popular method for it, would anyone here recommend it? that, or another reliable method? Thanks!

I think Nick felt that regardless, the 2g would be too slow to run it. I replaced mine with a 4g -- wish I'd done it sooner!

Yeah, we have two reasons for requiring iOS 5. The development features available to us are compelling, but also, the performance on the devices which can't run iOS 5 is just not there. (I had to cut out my much-treasured iPhone 3G first when making the switch.)

好可惜... but I understand that decisions have to be made.

So to sum it up, it'll have to be at least iOS5 and iPhone 4? 3GS is no good either?

I'm on 3GS and it runs fine. I think nothing below 3GS (i.e. not the original iPhone 3)

iPhone 3GS works, but not 3G. iPod Touch 4th gen works, but not 3rd gen. All iPads work.