Given that Android Police has had a pretty good track record with rumors, leaks, and uncovering information ahead of their official announcements, perhaps Russakovskii’s claims might have some merit to them. It is unclear as to what exactly Android 5.1 Lollipop will feature, but we can only assume that the usual bug fixes will be part of it, such as improving the battery life of devices, WiFi issues, notifications, and OK Google voice controls.
Russakovskii claims that Google has been having some issues with battery life regarding the update which might explain why it has been delayed (meaning that it should have been released earlier than expected), but it seems that the problem could have been resolved and that we can expect it to be released this week. Take it with a grain of salt for now, but do check back with us then for the details.