We spend a lot of time here at Lifehacker wondering when various models of phones will get OS updates, and frankly it's amazing that we haven't seen this sooner: Telstra now has a page detailing when updates will be released for its current line of phones.
It would be more helpful if there were fewer 'TBC' dates and a little more specific information than just the target release month, but even so it's an improvement on the previous method of hunting down confirmation on Twitter posts and random blog updates. Unsurprisingly, Apple isn't featured, but since it controls its own software updates, that's understandable. Thanks Beau for the spot!
Telstra (go to the Software Updates tab)