Android One was Google's mega strategy to reach 'the next billion' people. To achieve this it had to target the 'mass market' and the take on the biggest challenge of combining 'affordability' with 'latest technology'. The most unique feature of these phones is that Google itself handles the OS updates.
Months have passed since Lollipop was officially announced and started rolling out to the Nexus family, but there is no official word from Google as to when Android One devices will get the 5.0 update. This may be because Lollipop is still buggy and major OEM's have also delayed the update. Htc who promised Lollipop update on all of its phones within 90 days of the software’s availability from Google issued a statement on the company’s website
“We’ve been working hard in the labs with Google and our carrier partners ever since the code release and are making great progress so far, but if you’ve been following the progress of this rollout you will know that Google has had to address several issues with this release. We’ve been diligently working to fix some of them on our end and incorporating Google’s fixes as quickly as possible, but despite everyone’s best efforts some carrier versions of the HTC One (M8) and HTC One (M7) will not meet our 90 day goal, which is February 1st."But there is some good news to all Micromax Android Canvas A1 users. In response to a comment on Google plus post Micromax Mobile replied that Lollipop update might be rolled out soon. Though the post didn't give a specific date for the update.
Since Google handle the software updates, we can assume that the time frame will be the same for the other two Android One phones also. Some posts on other websites indicate that the update is expected around Feb 25th.
UPDATE:Google confirms the 5.0 (5.1 is expected as Android One devices launched for Indonesia run 5.1 run out of the box) update for Android One.Android One users in India — you'll be getting the Lollipop update in the next few weeks. @androidone