FWIW, while this says "Sold by: Colin Percival", the FreeBSD 10.3-RELEASE images were built and uploaded by the release engineering team; my only involvement this time was to let the Marketplace team know that a new release was available. The FreeBSD project takes the issue of "bus factors" seriously, and while I started the FreeBSD/EC2 project the intention has always been that it would get handed off to the FreeBSD release engineering team; with 11.0-RELEASE we should finally have the last bits sorted out and it will show up in the Marketplace as "Sold by: The FreeBSD Project".
EDIT: Hijacking my own comment slightly, since it's at the top right now: I'm not sure why 10.3-RELEASE being in the AWS Marketplace is a story when 10.2-RELEASE, 10.1-RELEASE, 10.0-RELEASE, 9.3-RELEASE, 9.2-RELEASE, 9.1-RELEASE, and 9.0-RELEASE being in the AWS Marketplace weren't. The hand-off from me to the release engineering team has been gradual (made slower by the fact that we only get to try something new once every 6 months!) but as far as users are concerned FreeBSD has been in the AWS Marketplace for years.