Apple has released an update to iTunes, bringing the latest public release of the software to version 10.5.2. This update contains small fixes for an audio distortion problem that may happen when playing or importing audio from some compact discs. Beyond this fix, the program contains some undocumented iTunes Match refinements.
The update should be available via Software Update for most users, but can also be downloaded directly from the iTunes 10.5.2 download page. (Note: some browsers are currently still showing the page for version 10.5.1, but Apple's link will still direct you to the correct download.) The update is around 102MB as a standalone download for OS X, and around 66MB to 68MB for Windows systems.
In addition to the iTunes software update, a firmware update for Apple's Thunderbolt Display is available. This update is supposed to address a power-handling issue that resulted in loud fan noises coming from the displays, and includes a few other stability improvements. The update, which requires OS X 10.6.8, or OS X 10.7.2 or later, is a small 942KB application that when run will give you onscreen instructions for how to apply the update.
As with all firmware updates, be sure your system and the display are plugged into a reliable power source, and do not disturb the update process, as a faulty update can render the display inoperative.