Microsoft has announced that they will be delivering a new update in August, called the "August Update" and rather than bundling a bunch of updates together like they did with the Update 1, they will now switch to a monthly roll-out of improvements.
Microsoft has said that in August, the following updates will be included for Windows 8.1 users:
Precision touchpad improvements – three new end-user settings have been added: Leave touch pad on when a mouse is connected; allow right-clicks on the touchpad; double-tap and drag.
Miracast Receive – exposes a set of Wi-Fi direct APIs for Independent Hardware Vendor (IHV) drivers or OEM drivers to develop Windows 32-bit applications that run on all supported x86-based or x64-based versions of Windows 8.1, enabling the computer as a Miracast receiver.
Minimizing login prompts for SharePoint Online – reduces the number of prompts with federated use in accessing SharePoint Online sites. If you select the “Keep me signed in” check box when you log on for the first time, you will not see prompts for successive access to that SharePoint Online site.
Further, the post explicitly states that there will not be an "Update 2", which kills quite a few rumors. As with other updates, this one will be delivered via Windows Update.