Also, Siri needs to stay somewhat exclusive. If Apple were to release Siri to all platforms, Siri wouldn't be such a big selling point. Siri is such a big selling point that Apple needs to make it a big deal on certain products. Maybe the iPod Touch for example, would skyrocket sales, just due to the feature. Keeping it exclusive will have a much larger effect on sales.
Maybe iCloud can be synchronized with what Siri does on the iPhone. When you set a reminder, iCloud can send that reminder to your MacBook or iMac. This would be more productive, and save money.
So, what do you think about Siri's future? I'm almost positive that you're thinking the opposite of me, but I'd love to hear other people's point of view.