iOS 5 will be available as a free software update for iPhone 4, iPhone 3GS, iPad 2, iPad, iPod touch (fourth generation) and iPod touch (third generation) this fall. Some features may not be available on all products.
Unfortunately, Apple doesn't spell out what, exactly, won't work on the slower iPhone 3GS and third generation iPod touch. But some research from 9to5Mac and Banolka on YouTube gives us some ideas, at least in the beta.
What we know works:
- Notification Center
- Twitter Integration
- Newsstand and Periodical Store
- Grid Lines and Exposure/Brightness Settings in Camera app
- Reading List in Safari
- Volume Up Button to Take Pictures
And what doesn't (but it's a short list, so far):
- Image editing (red eye, cropping, magic wand)
- Reader is missing (we've heard mixed reports on this)
So, it looks like 3GS users are in good shape going forward, but, of course, all of this may change as the beta period goes on and we get closer to release this fall. What might be most difficult to implement for the 3GS is a feature that doesn't even exist yet. We reported earlier today that Nuance/Siri Voice Features might still be included in iOS 5 and I wouldn't be surprised if that particular feature was not enabled on the relatively underpowered 3GS.