Actually BlackNMild you point something out that is important to understand.
Some of these limitations are not created because of the hardware creators, but because of licensing and partnerships.
Apple didn't allow facetime via 3G because AT&T and other partners didn't want the bandwidth eaten up with video chat...not to mention people realizing that video and internet phones are the future and the current cellphone plans being dictated to us SUCK.
Now, yes...Apple should have allowed Software upgrades to function on ALL hardware it is capable of. However, they are still a business...and businesses have to promote you buying new products. Nobody would have bought a 4S iphone if Siri would have worked with the old model. Unfortunately Apple, didn't have a compelling hardware upgrade for their phone, and just had a minor update with some really nifty software upgrades.
Actually, this is the problem with the Cellphone model wars. Every year and month a new greater phone is released...and not every year is it really worth upgrading your phone or computer for that matter. Not even every 2 years...the iphone 4S will be completely functional for all activities I would ever need a phone for...for at least 3-4 years. However, if a new model isn't made every year...people say Apple or Samsung, or whoever is out of touch and losing the market. And market perception is everything.
This is actually what killed Nintendo in the first play with the Wii...people assumed it wasn't worthy a true gaming system because of the casual market and lower powered specs.