The OSHW iMX233-OLinuXino-Maxi was designed on 4 layers and everything worked from the first prototype, so we moved forward and re-routed the iMX233-OLinuXino-Mini version which have no Ethernet on 2 layer to unleash the hobby designs with iMX233.
Do you see the weird drill slots around the mount holes? This briliant ides was proposed on Yahoo Groups OLinuXino forum, we made the board to fit in low cost plastic enclosure, but someone suggested that many would not need plastic box if they want to put this board in industrial enclosure, so mounting holes are necessary. The Maxi and Mini boards are so dense populated that you can see there is not much space for mount holes, then somebody proposed to make this drill slot design which allow mounting but if one want to place the board in box can simple bread them away and put the board in the box. This just show how viable is the open source idea, many heads think better and find smarter solutions than one :)
Now have to test if the DDR RAM will work reliable at full speed with 2 Layers.
iMX233-OLinuXino-Mini is OHSW as well and the CAD files will be available on GitHub once we debug and make sure everything works as expected.