Let’s talk Siri: iOS app is a goner, the trouble in Canada, Siri hacked to run on the A4 iOS devices

Siri, an intelligent virtual personal assistant, is being advertised as the iPhone 4S's killer feature. A live demonstration that Apple's iOS software chief Scott Forstall gave yesterday (video after the break) wowed the crowed of tech journalists who've seen it all. Rightfully, though – Siri is nothing short of breathtaking. Siri can be seen in Apple's onstage demo accomplishing a wide variety of complex tasks with an incredible ease. It delights with conversational responses to inputs: You can tell Siri to move your appointments around, remind you to call Mom when you arrive at Starbucks, ask for latest weather and stock info and much more.

Heck, it even inspired T-shirt. Us? We can easily imagine automotive infotainment applications and expect to see Siri-enabled car systems in the near future. Back to reality… As we're processing yesterday's announcement and gleaning noteworthy tidbits and web reports, three major topics spring to mind.
First up, the Siri Assistant app is no longer available for download on the App Store, which makes sense now Apple's gone all out with Siri integration in the iPhone 4S. Apple is adamant that Siri only works on the new iPhone 4S due to its substantial computational needs. Only the iPhone 4S' "twice as fast" dual-core A5 chip with 1GB RAM and digital signal processing capabilities is powerful enough to handle Siri's natural-language processing and artificial intelligence features, Apple would have us believe – even though Siri offloads some heavy lifting to Apple's servers.
In fact, as pointed out by the ModMyi blog, jailbreak hackers iH8sn0w and Gojohnnyboi have successfully ported Siri to the fourth-generation iPod touch which runs Apple's previous-generation A4 processor (just like the iPhone 4). It's a proof of concept and as such prone to bugs and erratic behavior, but it does tell us Apple may have limited Siri to the new iPhone 4S for marketing purposes. On the other hand, it's still inconclusive as iH8sn0w warns that "at this point, we're unsure of whether Siri requires certain hardware components or not".
UPDATE: Gojohnnyboi chimed in with this clarification:

We didn't "port" Siri to anything. We investigated it, and verified the claim that it is not able to run on old devices.

Second, Siri is a no show on Apple's Canadian site. Not a single reference or mention. Plus, Apple's gone to the trouble of editing out the Siri parts from the iPhone 4S promo clip hosted on the Canadian site. As of now, Siri is only being promoted on Apple's web sites in the U.S., UK, Australia, France and Germany. Nuance issues or, more likely, licensing problems could be holding off the Siri launch in Canada. It could also be a patent-related issue and a good example of that is the Skype app which wasn't available in the Canadian App Store for a long time due to patent woes, as pointed out by a Twitter user gragib. It's also a tad peculiar that Apple chose to launch Siri as a beta product. Considering Siri's prominent positioning throughout Apple's marketing, it's an eyebrow-raising move, to say the least.
Update: The Vancouver Sun is now reporting that Siri will indeed be available in Canada. They claim Apple isn't listing the service on their Canadian website due to the fact the "French" option doesn't support Canadian French. They do seem to confirm that all the supported languages will be available, however.

"If you choose French, it is the French of France, not Quebec. Hence, Apple is not including Siri on its Canadian web site because, strictly speaking, there is no Canadian version of Siri. Apparently that is still to come."

Siri will initially accept spoken input in English, French and German, but Apple has promised to add more languages, phrases and enhance its intelligence down the road. In fact, 9to5Mac has learned that Siri wields a dictionary spawning hundreds and hundreds of everyday phrases and spoken commands. Additionally, Siri co-founder Norman Winarsky exclusively revealed to 9to5Mac that Siri's modular architecture allows Apple to replace the Nuance-driven text-to-speech component with any other speech synthesis technology.
An excerpt from our interview with Winarsky (plus Apple's live demo of Siri):

When we first built Siri, we use Vlingo for speech recognition and as such, at the time of purchase the speech recognition component is modular. Theoretically, if a better speech recognition comes along (or Apple buys one), they could likely replace Nuance without too much trouble.

Perhaps the best way to understand Siri beyond Apple's shiny promotional video is to have a look at the live demo Forstall gave yesterday to the crowd of tech journalists at Apple's Cupertino campus – you're definitely going to love it.
Of course, questions remain of Siri's practicality and its fitness for real-life use. Do we really want to talk to our iPhone in public all the time? Of course not. But when jogging, driving, mountain biking, multitasking and what not, Siri could be a real time-saver, regardless of its futuristic allure. Thoughts? Hit the comments, we're all ears (pun intended, indeed).