A pair of images that appear to show a Notifications tile on the Start screen of a Lumia 620 and another unidentified handset have been posted to the XDA-Developers forums and Windows Phone PL. The icon on the tiles looks just like the one that appeared in screenshots from a Lumia 920 running internal Microsoft firmware that leaked out earlier this year. In the image above, we can see that the the asterisk in the Lumia 620's Notifications tile is present in its status bar as well.
Also on that Lumia 620 is a Live Tile that reads "1 Skype" and "1 Outlook." It's not clear exactly what this Live Tile is, but the fact that the user has alerts from two different apps suggests that it could be some sort of unified inbox where a user could view messages from both services.
Finally, the photo below shows four small Live Tiles grouped together, each of which is lit up and sporting a check mark in its upper right corner. It's possible that this is a feature that'll allow users to select multiple Live Tiles at once for quicker and easier Start screen management.
Microsoft is rumored to be prepping two noteworthy Windows Phone 8 updates for release in the coming months. The first, known as GDR3, is expected to bring support for features like large 1080p displays and quad-core processors. This update will reportedly come preloaded on hardware like the aforementioned Lumia 1520 and then roll out to existing products later in 2013.
Following GDR3, Microsoft is expected to introduce a major Windows Phone 8.1 "Blue" update in early 2014. This update is rumored to include a notification center, one of the most oft-requested Windows Phone features, along with several other goodies. Obviously it's kind of a bummer that Windows Phone users may be waiting several more months before a proper notification center is added to their OS, but hey, at least there are plenty of leaks to keep us occupied in the mean time!