Although Microsoft never officially announced that the Windows team will no longer be issuing service packs, that's widely believed to be the case. (Supposedly, the faster Windows iterations, starting with Windows Blue and Windows Server Blue, will replace service packs.)
As far as we Microsoft watchers know, Windows 7 Service Pack 1 was the one and only service pack for Windows 7 that Microsoft plans to release. (And Windows Server 2008 R2 SP1 was the only SP planned for Windows Server 2008 R2, as far as we know.) But just because there are no more service packs, per se, doesn't mean the Softies aren't providing the rough equivalent of what consituted a service pack.
As part of the myriad fixes and updates that Microsoft released on March 13, this month's Patch Tuesday, is the Slow Boot Slow Login (SBSL) Hotfix Rollup for Windows 7 and Server 2008 R2. This is a rollup of 90 hotfixes that were released after SP1 for Windows 7 and Windows Server 2008 R2. These fixes improve overall performance and system reliability of both operating systems.
Included are improvements to the Distributed File System Namespaces (DFSN) client, Folder Redirection, Offline Files and Folders, Windows Management Instrumentation (WMI), SMB client and Group Policy, as detailed on the Ask Premier Field Engineering Platforms blog. The recommended steps for deploying the hotfix on both the client and Windows Server also is explained on the blog. The Knowledge Base article lists all 90 of the included hotfixes.