Honestly, after watching the 45 minute presentation, there were a ton of interesting tid bits I transcribed word for word (that's what you see in all the quotes and the video is embedded if you prefer that).
For skimming purposes, I tried to bold the most important bits in the quotes, so it was straight from Siri's Co-Founder, CTO and VP of Design, Tom Gruber's mouth.
Honestly, skimming through the article quickly myself (it took me 3 hours total to write including watching the 45 minute keynote and transcribing the important bits) I can't see how you think it is low on substance, because there is a ton of it in there.
I'm honestly fascinated to see if Apple open's up the Assistant API to 3rd party developers as the Siri team clearly planned to pre-acquisition. In my mind it makes a lot of sense given the new "verb" world Facebook introduced, and I think developers would have a ball with it.