VC-1, the codec used in Blu-Ray, was developed by Microsoft. Microsoft using Blu-Ray isn't that big of deal. Here's a list of some of the patent holders:
CyberLink Corporation
Dell Inc.
Hewlett-Packard Company
Hitachi Ltd.
Koninklijke Philips Electronics N.V.
LG Electronics Inc.
Matsushita Electric Industrial Co., Ltd. (Panasonic)
Mitsubishi Electric Corporation
Pioneer Corporation
Samsung Electronics Co., Ltd.
Sanyo Electric Co., Ltd.
Sharp Corporation
Sony Corporation
TDK Corporation
Victor Company of Japan, Ltd.
Warner Home Video Inc.
The largest patent owner is Panasonic, not Sony. No single company owns Blu-Ray