Actually, they're not too bad to cross-compile once you know how, but it is hard if everyone who wants to compile for arm has to handle this difficulty. We have some cmake 3rd party build recipes for cross-compiling ros in the ECL repository (courtesy of Yujin Robot), but I'll be moving these to the Eros repository (hosted by Willow Garage - refer to
https://code.ros.org/gf/project/eros/forum/?_forum_action=ForumMessageBrowse&thread_id=33015&action=ForumBrowse&forum_id=88 for more information) shortly.
Eros is not really user ready yet, but I can move across the cmake build recipes for apr, apr-utils and log4cxx for you to make use of if you need them urgently.
Regards,
Daniel Stonier.