> Google Translate English:
> https://translate.google.se/translate?sl=it&tl=en&js=y&prev=_t&hl=sv&ie=UTF-8&u=http%3A%2F%2Fdeliriotecnologico.blogspot.it%2F2014%2F10%2Flinuxday-notebook-powerpc-da-costruire.html%23more&edit-text=

There's a proper English article in the author's other blog:

http://techuman.wordpress.com/2014/10/17/gnulinux-powerpc-notebook-project-at-linuxday-2014/

> if it's not too expensive

If it ever comes to fruition, it will be relatively (not necessarily prohibitively) expensive due to low production quantities alone.

> or too underpowered.

Concluding from the announced specs, the processor to be used is the QorIQ T2080:

https://morph.zone/modules/newbb_plus/viewtopic.php?forum=3&topic_id=7001&start=737
https://morph.zone/modules/newbb_plus/viewtopic.php?forum=3&topic_id=7183&start=921
https://morph.zone/modules/newbb_plus/viewtopic.php?forum=3&topic_id=7183&start=945

Up to 1.8 GHz with AltiVec isn't too shabby I'd say. Of course, they may clock it lower because of power dissipation, heat and battery life.