Colin Percival has gotten FreeBSD running on EC2: http://www.daemonology.net/blog/2010-12-13-FreeBSD-on-EC2.html This is great news for all those BSD shops out their waiting for cloud support.
Amazon finally launched a much requested (at least by us) DNS service: http://aws.amazon.com/route53/
Amazon also just raised their S3 object size limit to a whopping 5TB. (from 5GB) http://aws.typepad.com/aws/2010/12/amazon-s3-object-size-limit.html Now the race is on to see our favorite tools get updated with multipart upload support.
The biggest news though is Amazon finally achieving PCI DSS 2.0 Validated Level 1 Service Provider status http://aws.typepad.com/aws/2010/12/aws-achieves-pci-dss-20-validated-ser... (for EC2, S3, EBS and VPC)
For you mobile devs out there don’t forget to check out Android http://aws.amazon.com/sdkforandroid/ and iOS http://aws.amazon.com/sdkforios/ SDKs, which allow you to point your mobile apps directly at S3, SimpleDB and SNS.