I see that this is a new product release. If it's anything like the RX700 all-in-one I bought, You'll probably have to wait a year or more before it's completely supported by free drivers. The gutenprint print driver will probably be the first to get support, but it may be quite a while before the sane epson backend adds it specifically. Fortunately though, the epson backend has generic support for unspecified epson scanners, so you should be able to use it at a basic level right away.
But you can also get the official Epson drivers right now from avasys (follow the link in my sig). Unfortunately though, in addition to the fact that they use binary blobs, their code seriously sucks. They also focus almost exclusively on RedHat and Suse, so for Ubuntu you'll probably have to first try converting the RPM's with alien, and if that doesn't work try compiling them yourself. In my case, the iscan/epkowa scanner driver compiled ok on my Athlon K7, but I could never get the cups driver to build. And I could never get either one to work on my AMD64. Perhaps you'll have better luck with it.
Finally, if you feel like shelling out the money, check out turboprint and vuescan. They're both proprietary, but certainly of better quality than the avasys drivers.