OK, watched "The Christmas Invasion" and "New Earth"... whilst pining for Eccleston I do like Tennant, we're definitely into Tigger-instead-of-tiger territory, no doubt about that! The Xmas special had some amusing moments [loved the spinning killer tree] and the end was very interesting. "New Earth" did the old body-swap bit pretty well, especially the back-and-forth with the Doctor and Rose. I was a little skeptical about how quickly Cassandra got nice after entering Chip's body at the end, but it must have been his influence. I'm digging how the show goes back to previous episodes, weaving an arc even when it doesn't seem like it is. It encourages one to pay attention!
I like a lot of the little details, like Rose's mom turning around before the TARDIS dematerializes so she won't see it go. I also like that it's trying to make us think about the consequences of things.