The Nokia event is being held on the opening day of Microsoft's BUILD event (April 2nd), but it is being run as a separate event, in part because Microsoft's acquisition of Nokia Devices and Services division has yet to be completed.
From Nokia Conversations:
We’re packed, primed and gearing up for the Microsoft BUILD Developer Conference 2014. Are you?
What makes 2014 so special is the exciting Microsoft and Nokia partnership, and boy, have we got some treats lined up for you.
So when will you find out? Meet us here at Conversations on Wednesday April 2 where we’ll be revealing all.
The Nokia Conversations post includes a teaser banner, with a stylised "more", with the "o" replaced by a cycling series of icons. The icons can be identified as Nokia MixRadio, HERE Maps, Nokia Camera, Nokia Chat, a globe (possibly Nokia Xpress), and a clock.
The make up of the banner would suggest a number of announcements related to Nokia's exclusive Windows Phone apps and services. Windows Phone 8.1, which Microsoft is expected to formally announce the same day, will introduce a whole range of new APIs and functionality that could potentially be used to improve and add features to Nokia's existing apps and services.
For example, the Nokia Camera app is currently only able to provide limited access to the full resolution / DNG photos shot by the Lumia 1020 and 1520. An updated version of the app, relying on Windows Phone 8.1's new file and folder related APIs, could address this issue and provide full access for sharing and/or editing. Similarly, HERE Maps could be updated to take advantage of new geofencing APIs, potentially providing location based alerts and/or alarms.
Given the proximity of the BUILD event, there may also be some news around the related APIs for the Nokia services. Both Nokia MixRadio and HERE Maps have their own set of APIs, allowing third party developer to use music and mapping/location content in their own apps and services. In addition, the imaging team behind the Nokia Camera app, also develops the Nokia Imaging SDK, an update to which was recently announced at MWC (version 1.1).
With regards to new Windows Phone 8.1 devices, the scale and relatively late notice of the event would suggest this will not be a major device flagship launch, along the line of the Lumia 925, 1020, or 1520. However, a smaller scale launch, similar to the Lumia 620 or 625, is a possibility. Nokia has a range of Windows Phone 8.1 devices currently in development, but in our estimation the most likely candidate for next Wednesday's event is the Nokia Lumia 630.
Other devices currently in the late development stage include an international variant of the Lumia Icon (i.e. the Lumia 930) and a follow up to the Lumia 520 (i.e. Lumia 530).