I have just read this

Clicky

What are Google playing at? Won't this alienate early Android adopters? Why don't they make their later versions of the OS compatible with devices already out there?

I guess they want to take advantage of the latest hardware for new features. That's no reason for new apps not to work on old hardware though.
Thankfully I'm on 2.1 so I should be okay for a while.
Does iPhone OS have this issue?

Yeah, you have a beauty of a phone. It should serve you well. I hope that Android 3.x will run on it when it is released, or maybe you will upgrade when the contract runs out?

Not at the moment. So far every OS update has run on every handset and is updated when you sync. your phone to your computer (via iTunes). Not every feature comes across though. For example when iPhone 3.0 came out it allowed video for the first time on the 3GS but not the 3G all the other new features (like copy and paste) were enabled on all past handsets.

Who knows with then new OS (OS 4)? Some features like multitasking are not going to be available to phones with slower chips but I think other features such as folders for applications will be available as far back as the original iPhone. We will find out for certain in a month or two.

It could be a problem for the iPhone, we'll see the summer.

It would appear that as a new OS is released, developers start developing for it. So far, it seems that you need to keep up to date with everything or be left behind with apps that you can't update (due to an old OS).
So far, every OS released has run on every device.
With the original iPhones and iPod Touches not receiving the OS 4 update, we could see people being left behind...

Is this a fact now? The 2007 devices won't get OS 4 at all? So far every device has been updated with each OS. Oh dear I wonder if this means I will only keep my 3GS for three years.

That's what I interpreted from the keynote speech. Have a look in the iPhone OS 4 thread, I posted a link to the keynote. Jobs mentions it right near the end. iPhone 3GS will get everything*, iPhone 3G and iPd Touch 2nd Gen will get most things.

Those early devices did not have a lot of memory did they? 4Gig?

Maybe that is the limitation. With things like a system wide spelling checker being added and the OS growing with hundreds of new features maybe there is not enough room for the OS and still leave space for a meaningful number of applications and music storage.

They didn't have much storage, though I think the minimum was 8GB...If people really wanted to use their iPod in anger, they'd have upgraded. I don't think it's a space issue...

That's pretty much word for word. I'm wondering what Jobs meant by "pretty much everything", perhaps current iPhone 3GS' won't be able to do some iPhone OS 4 stuff?

It could mean stuff that is hardware specific to the new things on the new iPhone? But because they haven't announced it yet they can't say what they are yet.

128MB RAM, the 3GS and 3rd gen Touch have 256MB RAM.

The limitation on Android is down to the service providers. Motorola announced an update from 2.0 to 2.1 for the Droid as "being released today" 3 times before their service providers actually let them download it to customers. The same is also true of Windows Mobile and Symbian. The users only get the updates that the service providers allow - or they have to look around for unofficial sources and download the vanilla image, which will lose them some of the special features that were applied by the service provider.

HTC have released several bug fixes for my Touch Pro, but none of them are available for update, because they haven't been approved by O2 Germany. If I download the "fixed" version, I'll lose the TomTom app provided by O2, as well as a couple of other things.

I have only seen one Android phone in the wild. The owner, was in charge of a university computer system, was very technically capable and had it linked into the university computer system, to warn him of any problems where ever he was. He showed how capable Android could be. For specific uses I would imagine Android more useful than any other phone OS out there.

Any guesses as to why the service providers should drag their feet about updates? If they want to establish a rival platform to both RIM and Apple and I guess also to OVI you would think that they would be keen to dollop on the feel good factor for making the Android choice.

I have not seen one yet. The tech pundits love them so I am sure they are good. I am not sure why mass adoption has not occurred yet.