Since Microsoft began offering downloadable recorded content for the company's conferences and events, there's always been at least one community member that produces an excellent solution for obtaining selected content for offline use. In this case, Claus Nilsen is this year's go-getter, providing a PowerShell script that uses WinForms to make the solution both functional and elegant.
The script actually works to pull down content from TechEd, Build, SharePoint, and Lync conferences – and from multiple years.
To locate exactly what you want, choose to sort by category and speaker, and then select the type (videos, slides, or videos and slides) of content you want to download to the local computer.
You can download the PowerShell script from the TechNet Gallery here: Download sessions from Channel 9 (TechED, BUILD etc)
P.S. If you have trouble running the script, make sure to set the proper Execution Policy.