The invention, which in 2009 Apple called a "Reduced Size Multi-Pin Male Plug Connector" describes a 30-pin dock connector for "high-speed communication standards," citing USB 3.0 and a "dual channel" DisplayPort.
The name "Thunderbolt" wasn't mentioned (unsurprisingly, given that it only launched in February 2011 on the new MacBook Pro) but the patent's multiple mentions of a "dual channel" DisplayPort suggests the same technology.
Thunderbolt combines Intel's PCI Express and DisplayPort into a single connector for theoretical transfer speeds of 10 Gbps (fast enough to download a full-length Blu-ray movie in under 30 seconds). For more, see Intel's Thunderbolt: 10 Things You Need to Know.
Based on the patent application's description, it's pretty clear the invention is also intended to reduce the size of Apple's mobile devices:
"Electronic devices such as media players and related devices have become ubiquitous over the past several years. As they have proliferated, the types and styles of electronic devices have diversified. During this time, a theme has been that consumers want more functionality packed into an ever-decreasing form factor.
"At the same time, many new high-speed communication standards have been developed. Examples of these new standards include the new high-speed USB 3.0, DisplayPort, and others. Although it is desirable to have an electronic device such as a media player be able to use these new high-speed communication standards, these new standards are often tough to meet." (emphasis added).