Now that Microsoft's latest version of Windows is officially out, we can see the update process in a little more detail. The Update Tuesday/Patch Tuesday schedule is not being used for Windows 10, instead a series of "Service Releases" will be put out periodically (presumably with any urgent security patches being pushed out as needed).
The first Service Release looks to be coming soon at the end of August, with another possibly in October. The latter may bring some added features too, not just bug fixes and tweaks. The Service Release should not be confused with the older "Service Pack" concept, in which a large number of fixes (and sometimes functional changes) were "rolled up" and released as one big update.