Episode 3 was fine; nothing big since it was a set-up for the next episode and everything. I LOVE the artwork by Yoshida of Eureka and baby Ao in the picture.
I also like the addition of Eureka near the moon in the OP (as well as the necessary hair color change for Ao in the OP and ED).
Also, not entirely AO-related, but did anyone catch Hadena Fansub's subbed version of episode 51? (The famed alternate ending to E7 that was never aired, but had dialogue written out and performed by the seiyuus in 2006 at a Sony Music Festival)? BONES recently put it out on Japanese televisions a few weeks ago and Hadena graciously subbed it.
I sobbed like a baby the entire time.