We never expected to see the Android based Nokia devise at MWC 2014 but then it just another experiment being done by Nokia to get their sales up. Increasing the popularity of their devices and simultaneously increasing the users for Windows Phone OS is obviously an unachievable target, especially when people have lost their interest in both of them. So by using Android Nokia may be planning to increase the sales of their Nokia smartphones and then thinking of Windows Phone OS later.
As per the leaks provided by evleaks (which are genuine most of the time), Nokia might hold an event to reveal their new Windows Phone OS based Lumia devices. Out of which, one will be successor of Nokia Lumia 620 (named as Nokia Lumia 625 or 630) and the other one could be the Nokia Lumia 930.
Usually, the new version of the Nokia Lumia devices are equipped with the updated version of Windows Phone OS and the same pattern is followed at this point of time also. The new Windows Phone OS will have the background on the start screen, which was utterly missed on this OS and then as to likes of Siri or Google Now, Windows Phone OS will have Cortana. Stay tuned as we will keep you updated with any details related to this event.