The OLPC question is a little tricky. I have several btest boards and ... the dram on each one is different, with different timings. Two of them have custom dram timing settings (it's a long story). This target is going on 5 years old and I think it ought to be yanked -- anyone have one? It's a real distraction and I don't see the point in keeping it on when it just confuses people.
same for rev_a. I just don't see the point, given that if you have a board, you're not supposed to :-)
ron