Microsoft is poised to send out invitations to press and other guests -- most likely in the next few days -- to its expected Spring launch event that's likely to be more about Windows Cloud than any crazy new Surface form factors.

The Spring event is codenamed "Bespin" and likely to happen in early May, sources say. Bespin is a fictional planet in the Star Wars movies and books. "Cloud City" is located on Bespin. Cassim Ketfi at Numerama.com, with whom I've been collaborating on the latest rumors, is hearing the same Bespin/May event talk that I am from his own sources.

Windows Cloud is a new edition of Windows 10, which first showed up during testing of Windows 10 Creators Update, but which Microsoft officials have yet to acknowledge publicly/officially.

As I wrote in January, despite its name, Windows Cloud seemingly has little, if anything to do with the cloud. As testers confirmed, Windows Cloud is a simplified version of Windows 10 that will be able to run only Unified Windows Platform (UWP) apps installed from the Windows Store. The new Cloud edition is similar to the version of Windows 10 formerly known as Windows RT or the Windows 8.1 with Bing SKU.

Windows Cloud is not a version of Windows 10 streamed from the cloud or a new Windows 10 subscription offering. It's just a simple (and presumably more secure and manageable) version of Windows 10 that will be able to be upgraded to Windows 10 Pro (for some amount of money). Windows Cloud could help Microsoft better compete with Chromebooks and Chrome OS, though Microsoft officials may not publicly position the offering that way.

As I blogged recently, my contacts are saying Microsoft will not take the wraps off a Surface Book 2 PC at this event. My sources say a Surface Book 2 is still in the cards, but it's not ready yet. For now, Microsoft is focusing on selling its existing Surface Book and Surface Book with Performance Base stock.

I've been asking around as to whether Microsoft may launch a Surface Pro 5 at this Spring event. Some of my contacts believe this could happen, but caution that the coming device may be more evolutionary than revolutionary.

I've heard the same as my Windows Weekly colleague Paul Thurrott: Anyone hoping for USB-C may be disappointed. An Intel Kaby Lake processor is likely in the new Surface Pro model, some of my contacts are saying. But there will be no new power connector or other ports, my sources say.

If it isn't obvious, Microsoft officials are not commenting on anything about the Spring launch.

I've heard from a few contacts another rumor that Microsoft may have a new Surface-branded device to show off at the Bespin event.

Digitimes -- which has a spotty accuracy record, especially regarding Microsoft announcements -- claimed recently that Microsoft had begun manufacturing clamshell laptops. This doesn't really fit with the self-proclaimed mission of the Surface team, which is to establish new device categories in order to expand the overall Windows device market.

I have been wondering whether Microsoft is readying some type of PC/tablet that will run Windows Cloud. Others are wondering the same. This device could potentially be branded "Surface 4" -- unless Microsoft wants to claim it's inventing another new product category. I don't have any solid tips on the kind of processor that might be inside such a device..

Microsoft ceased manufacturing Surface 3 tablets as of December 2016. Surface 3 was an Atom-based tablet that started at $499 when it was introduced in May 2015, was aimed at students, families, and other budget-conscious users. Microsoft shipped Surface 3s with Windows 8.1 but the devices were upgradeable to Windows 10. Microsoft also introduced LTE versions of the Surface 3.

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