Are the objective-C and Cocoa books being held a bit longer waiting for NDA on iPhone OS 3.0 to be lifted so some cross over subject matter could be included (Core Data for example)?
Any word on a possible MacRuby book yet? Looks like that project is really steaming along. Especially after seeing the two screen casts From Mike Clark on the Studios site.
For a cover pic, I recommend a Granny Smith or Yellow del. apple partially covered with that red candy you use for those candy apples you get a county fairs and what not. Partially so you can still see the apple underneath it (bottom 1/3 or so) but the candy coating appears to be slowly flowing down the apple. The choice of Granny smith or Yellow del for the actual apple is for color contrast against the red translucent candy coat. The green Granny smith would look best (better contrasting colors), but prag has been putting a lot of green apples on the cover of there books already (3 including the objective-C) so it might be a nice change to go with a Yellow apple instead. just a thought.