X-link to the DRM-free thread for some new bundles:
Humble Book Bundle Network Security & Certification presented by Wiley consists of mostly highly-specialized technical training computer books for professionals.
The Winter Wonderland Game Bundle contains non-fiction books about (mostly video) games and the gaming industry. There's genre history, creator interviews, developer inspiration stuff, classic game retrospectives, and a rather interesting-looking book by a professional game translator about localizations, with examples of selected translations from real video games, explaining choices made due to cultural differences and other factors.