Windows 7 already has built in DivX support in the current beta. Hidden inside the various changes since beta for the RC is a change to Windows Media Player to natively support the .mov files,
Improved playback support for video content from digital camcorders and cameras
Customers loved the increased range of formats natively supported by the Windows 7 Beta, but noticed areas where they wanted broader support. For example, one was unable to seek to a specific spot in the video in Windows Media Player or Windows Media Center for AVCHD content that was imported from a digital camcorder. We've addressed this. Also, while the support for video from some digital cameras worked great, we also got feedback about supporting a broader set of devices out of the box. We've since added support for Windows Media Player to natively support the .MOV files used to capture video for many common digital cameras.
This is a great addition to the RC along with various other changes. No longer we need to download Apple QuickTime or other alternatives like VLC Media Player, just to watch .mov files!
What are the other (possible) codecs do you think Windows 7 should support natively?
Thanks to Techradar for the heads up!