Currently it recommends kernel version 3.8 or greater. This means that if you prefer Ubuntu then you need 13.04 or the ability to upgrade the kernel.
It also currently requires usage of AUFS which means that you need the AUFS kernel module installed. So, if you have a supported kernel then you still might need the ability to modify the kernel. They are working on supporting alternate implementations such as BTRFS though.
EC2 is a great option right now and it's what I'm using.
I agree with another comment mentioning this is the future. However, I wonder how long it will be before something like "Erlang On Xen" becomes more widespread, cutting out the OS completely.
ETA: I love watching this project, it has really taken off and the maintainers have been making fast progress. It seems that as soon as I run into a show stopping problem, it's fixed the next day. It's a bit inspiring and makes me look at the progress I have made on my own projects. ;)