From F-Secure:
Centrino is not just a processor, it integrates WLAN and other features for laptops. The vulnerabilities are not related to the processor itself but to the wireless features.

The vulnerabilities are pretty awful. Worst of them "could potentially be exploited by attackers within range of the Wi-Fi station to execute arbitrary code on the target system with kernel-level privileges". So at least in theory, somebody could write a WLAN virus that would jump from one laptop to another if the laptops are too close to each other.

Patch now.

IBM/ThinkPad users - Run software installer and get the latest software patches now.
http://www-307.ibm.com/pc/support/site.wss/document.do?lndocid=MIGR-4ZKMCT

Otherwise, grab this ridiculous 129 MB installer file here, from Intel: http://support.intel.com/support/wireless/wlan/sb/CS-023065.htm