Microsoft is working to deliver an "Apollo Plus" update to Windows Phone 8 in the first quarter of next year, according a tweet from @Football4DA and reporting from The Verge. The update is likely to fix a number of bugs and performance issues, but may also include new features such as VPN support, and improvements in WiFi handling.

The Q1 2013 timing would fit with previous Windows Phone update cycles, such as the arrival of "Tango" this year, and "NoDo" in 2011. Thus far major updates to Windows Phone have arrived in the second half of the year (Autumn), with minor updates delivered in the first half of the year (Spring). There's little doubt that an update will be delivered, but what exactly it will include is less certain.

The Verge note that their sources indicate that Apollo Plus is not a major update:

Apollo Plus will bring new features to Windows Phone 8 that weren't fully in scope for the initial release. This won't be the next major version of Windows Phone, but more of a point update to push fixes and features.

However, the update will bring a small number of new features:

We're told that Microsoft is preparing to include VPN support in Windows Phone, a missing option since the reset of Microsoft's mobile OS efforts, that will allow corporate users to connect to work systems — this feature may make it into the first Apollo Plus update. A Wi-Fi connection fix is also planned to let connections always remain on, alongside some audio improvements.

This platform update will likely be in addition to manufacturer specific updates from Nokia, HTC, and Samsung. Past experience suggests that Windows Phone devices receive small optimisation updates from manufacturers two to four months after the release of the device. Of the existing Windows Phone manufacturers Nokia has been the most active in providing updates, a trend we expect to continue.

All the update will be delivered over the air, either over 3G (smaller updates) or WiFi (small or large updates). From Windows Phone 8 onwards a PC is no longer required to update a Windows Phone 8 device. This contrasts with Windows Phone 7.5 devices which can only be updated via PC companion software.