I don't normally cross-post, but I'm delving in to the Heartland Payment Systems data breach. With over 100 million transactions processed monthly (apparently), and the fact that the malware appears to have been sniffer-based, this will likely be the biggest data breach so far.
Credit to Heartland for dealing with it so well thus far (except maybe the possible obfuscation factor of waiting until Obama-day to release it).
I wrote a blog about the breach on Frequency-X earlier today -- Largest Data Breach So Far? Heartland Payment Systems.
The Washington Post has more background here (I wish I'd found it before I posted to Frequency-X...)