Yes, its official, Canonical (makers of Ubuntu) and ARM have signed a deal to bring the complete Ubuntu distribution to ARM Cortex-A8/A9 processors (ARMv7 architecture). Expect the builds to be ready by April 2009. These netbooks power a full day no-recharge functions. But well only when the true devices come in, can something be said about them.
I also hope, that by meaning "complete Ubuntu distribution", they also port the gcc natively to ARM. Then, truly, new ARM based applications can be developed without the need for the now ubiquitous PC.
More info: http://www.arm.com/news/23761.html