It looks like the new Windows Phone 8.1 is likely to come soon as someone has evidently found the reference of the same inside a file for an application. However, it this turns out to be true, Nokia should be the first one to run towards it. An obviously it'll be called a Windows Phone 8.1. While hacking the Windows Phone Store to download other OEM's exclusive apps, Windows Blog Italia came across the file which makes clear reference to Windows Phone 8.1. If the leak is genuine than the OS should also be undergoing a testing phase this year itself.
To recall an incident early this month when a Nokia Lumia 920 was bought from eBay had parts of the Windows Phone Blue update including an improved calendar, and a new notifications page. Microsoft not only bought back the phone from the buyer, it also gave him a free Nokia Lumia 920. This probably shows some possibility of a Windows Phone 8.1 update coming as soon as Q3.
This leaked evidence of the probable Windows Phone 8.1 confirms that the next version of the OS will be called Windows Phone 8.1, and it is already in testing. The Windows Phone 8.1 may be is speculated to come before 2014 starts.
This leak is undoubtedly a clue that confirms that Windows Phone 8.1, as well as Windows 8.1. Although the features Windows Phone 8.1 will bring with it is still not disclosed or leaked so far but this leak however has undoubtedly hit the fans real hard.