According to WinBeta, the internal builds of Microsoft's Windows 10 operating system have jumped from the 10060s-range to the 10100s. This mirrors the activity before January's consumer event, which led to the release of 9926. What this likely means is that Microsoft has forked internal development ahead of their BUILD 2015 conference, which takes place between April 29th and May 1st.
I expect that they will release a new, highly-tested build in the 1006x-1008x range to both Fast and Slow rings, like 9926 was, at or around the time of the event. Meanwhile, new and experimental features will land on the 10100 branch. The interesting question is: when will we see that later fork?
If Microsoft dedicates themselves to rapid releases, it might not be too long for users in the Fast ring, or a faster-than-Fast ring that they could potentially announce at the event. With the visibility of BUILD, it would be a good time for them to shake up their release cycle. They really cannot afford to relax quality control any more significantly than they did with 10041 without assurance that Insiders get the message. The journalist attention of the conference would likely do it though.
Alternatively, the released build might be classified as a developer preview that is expected to stick around for a while. If I needed to guess though, I doubt it. As stated earlier, it will probably be a highly QA-tested build for Slow ring users, but I see little reason for Microsoft to throttle down the more enthusiastic users. When 10049 was the last build for Fast users, you could say that they were not wanting to overshadow BUILD. That obviously does not apply after the conference is over, and I cannot see anything else further on the horizon.
That is, of course, unless they are getting cold feet about releasing not-fully-baked builds to the public.