You'll have to buy a new ipad4 with the A6 processor!
Seriously ? Couldn't you be bothered to do the slightest bit of research ?
A few milliseconds with Google, or on the Apple website would have yielded the iOS What's New page on the Apple website "www.apple.com/ios/whats-new/"
It quite clearly shows there that iOS 6 is compatible with iPhone variants 3GS, 4, 4S and 5, and both the original iPad and the new iPad 2. It also quite clearly shows the small number of limitations if you run it on older devices (this varies model by model).
These limitations are not set by Apple because they want you to buy a new iPhone, its because the performance of older devices don't enable the newer more demanding applications to run.
Having said that no doubt there will be a new model sometime next year.The down side to these upgrades is that any sound boxes or connectors won't work because Apple have decided to introduce a new smaller version.
Oh right... and your favourite goody-two-shoes phone manufacturer, Nokia, Samsung or whatever wouldn't do that ? Believe me, I've been involved in the IT industry a long time.... if there's a potential technical or commercial advantage to be had, then the associated action will be taken without much regard for the customer base, no matter what the name is on the door.
Remind me, who's the primary developer of Android following the acquisiton of Android Inc ? Oh yeah, that's right, Google. Great track record they have on keeping features on their product portfolio don't they ?
Personally, I prefer the new connector to the old in many ways. For a start, physically its more robust, technically its faster and bidirectional.
I've no time for ignorant Apple bashers.