If you are running a phone that already has the GDR3 update, via the Developer Preview program, if you haven’t been notified already, you should have a look at settings updates and check, because there is a slight bump rolling out today. Even though it still needed wifi it was one of the quickest, smallest updates I have seen for the OS, taking only a few minutes to download. Before you get over excited, there’s not a lot to show for the update, taking the OS version from 8.0.10512.142 to 8.0.10517.150 through too 8.0.10521.155. After a quick browse through the settings there is not any obvious visual changes that I could find, so assume that this is bug fixes and maintenance driven. One thing to note is that this is the same OS build that the Lumia 1520 released with.