According to his FreeBSD on EC2 blog post, version 9.0-CURRENT of FreeBSD is now available in the US East (Northern Virginia) region and can be run on t1.micro instances. Colin expects to be able to expand to other regions and EC2 instance types over time.
The AMI is stable enough to be able to build and run Apache under light load for several days. FreeBSD 9.0-CURRENT is a bleeding-edge snapshot release. Plans are in place to back-port the changes made to this release to FreeBSD 8.0-STABLE in the future.
Congratulations to Colin and to the rest of the FreeBSD team for making this happen. I have received a number of requests for this operating system over the years and I am happy to see that this community-driven effort has made so much progress.