Did you guys know, that my current 7B74 worked with that update too? I started software update and et voila.. there it was. I got a bit surprised about this. Thought there is a build-request that decides whether there will be access to new updates or not.
depends on the update. you won't be able to update to 10.3.1 from that build, of course, but you'll still be able to get updates to iApps and maybe some security updates, because they only involve separate software packages they replace.