When Microsoft released build 10130 of the Windows 10 Preview at the end of May, it said that it was holding off on seeding it to those on the Slow Ring because it wanted to first monitor how those on the Fast Ring would fare. Well, it seems that they fared well enough, as the company has just decided to begin pushing it out to Slow Ring users.
There is a potential gotcha, however. Some people have noted difficulties updating through Windows Update, and while it seems a little absurd, the easiest fix, per Microsoft, is to just reinstall. For that purpose, it released the 10130 ISOs last weekend.
Evolution of Windows' system icons up to build 10130
Build 10130 is probably very outdated as far as internal builds go, but as Microsoft is now focusing more on bug-fixing and user experience improvements than rolling out new features, it seems unlikely that the next build us regular folk get will be that exciting.
With Windows 10 set to launch at the end of next month, it seems likely that the next few builds are going to be very stable for normal use, which is really something that could have been said for a while anyway (as long as you didn't happen to bump into some of its more frustrating bugs). This really is shaping up to be one of those releases where it seems no one should be afraid about taking the plunge. There's no need to wait for a "Service Pack 1" as with previous Windows releases -- Windows 10 looks to be extremely stable right out of the gate thanks to its open development process.