Among the features added in Ubuntu Server 12.10 Alpha 3 (Quantal Quetzal) we can mention Juju Charm Store policy implementation, Juju Charm maintainer assignment, Facter integration with Juju, Tomcat 7, MAAS IPMI support, Ceph 0.48, OpenStack Folsom testing packages, Openstack instance architecture detection support, armhf cloud images.
They are still in the process to remove i386 Ubuntu Server CD image and are focusing on the 64-bit platform. Nonetheless, other supported installations mechanisms for i386, such as mini.iso and netboot are still present and users have access to them.
According to the developers, unlike the desktop flavour, they're trying to fit the 12.10 server image onto a standard CD image (703MB).
Download Ubuntu Server 12.04 Alpha 3 right now from Softpedia. Remember that this is an alpha version and it should NOT be installed on production machines. It is intended for testing purposes only.