A recent update to one of Nokia's own apps prompts users to upgrade their phones to Windows Phone 7.8 leading to speculation that the promised update's release might be imminent



From Neowin:

As of now, the only indication for that is the fact that there are some Nokia apps which require the 7.8 update. This is the case with both Ringtone Maker and Bluetooth Share. These apps were created by Nokia to bring some extra functionality to WP 7.5 users. However Ringtone Maker has always demanded version 7.8 ever since it launched in mid-December.

Bluetooth Share on the other hand was working perfectly until it received a pretty major update in the last couple of days. The update bumps its version number from 1.0 to 2.0.2.2 and it now prompts users to update their devices to Windows Phone 7.8 via Zune.

  Windows Phone 7.8 update release imminent?