AbdulAlhazred
Legend
I can't comment on the racial backgrounds of the book (due to the Mark of Justice on my forehead), but I'll say this: I was never a fan of "17 flavors of elves" from earlier editions.
They'll be fine Personally I never had any big hate on for sub-races, they never made a huge difference but could be handy to portray demi-humans as more diverse instead of being some sort of monolithic cultural group that is exactly the same all over the world (while mysteriously humans alone of all races have vast cultural differences). Not a NECESSARY part of the game, but interesting.
In any case if they are built using the character background mechanism of 4e just exactly how big a deal can they be? Slight differences in languages, a different skill choice, maybe different racial weapon proficiency choice, etc. Really, even if it involves being able to pick a different racial power it isn't that earth shaking. I mean we already have half-elves and humans that have a choice of 2 racial features. Why not give dwarves that choice too and call it "Hill Dwarf" vs "Mountain Dwarf"?
Obviously we don't even know enough about what the rituals changes are going to be to comment on them. Personally I was happy with the existing ritual casting rules and I have never fathomed what people's problem with them was. It is like everyone wanted them to just all be handed to them free on a plate with instant casting, get over it, lol. However if something pretty close to the existing mechanics still exists and it makes the mysteriously disliking rituals people happy I won't complain. Always interesting to see new ideas.
I'm going to have to say I hope themes have been redesigned to avoid forcing people to take them or be penalized and to acquire a theme AFTER the PC has been played a bit. That would make them ideal.
I don't really see where anything was really wrong with the existing familiar rules either. They could have used a bit of clarification on a couple rules points but as a basis they seemed pretty good. Some elaboration on the non-combat uses and characteristics of familiars and some new familiar related content would be quite cool though, they certainly haven't been mined for their full potential yet.
As far as professions go, I could REALLY lose that. It is actually pretty hard to see how any kind of meaningful rules could be added that did anything useful beyond what "Oh, you're background says you were a farmer, well have a +2 circumstance bonus to tell if that cow is sick" already does for you. I can imagine some "world building" guidelines that would bear on backgrounds though. Dropping in a chart of hiring costs for ordinary professions for instance would be good.