This is a great idea, good luck with it! A few small suggestions: 1) Often times, I find myself in a car or in an area with heavily limited internet (i.e., the subway). I think it would be beneficial to allow a "listen to the audio only mode", reducing bandwidth and/or ensuring I keep focusing on the drive (maybe like a "team podcast" :-) ) 2) In a similar vein, speech could be converted to text to make it searchable…
To answer your questions: 1) Audio-only updates are coming soon. And with the iOS/Android apps is a great I idea to "listen" updates as you drive. Really cool, and will implement this soon when the audio-only support is coming (will work too by "listening" to videos as well).
2) Search is coming as well. You're idea is cool (specially for managers to be checking into a project), and I am already thinking on making a JIRA integration that puts all the associated/tagged standups into its related JIRA ticket on the sidebar, but this could also work via the search (advanced) section! Text-to-speech is also something cool, let's see how it all goes, as it's also easily implementable using Google's Cloud Speech-to-Text :)