In my preliminary research phase I already asked for books, but one more thing: I've read that ExtJS 4.0 will be quite different, Sencha Touch 1.0 is more similar to ExtJS 3.x or to ExtJS 4.0 ?
Otherwise said: is it ok to learn sencha touch with extjs 3.x books or it would be better to have a 4.x book? (ok clear, there are no 4.0 books still), but what I mean is: ExtJS 4.0 seems to be a big change that will simplify also the learning curve. If this is true, Sencha Touch is on the 3.x or on the 4.0 side? And even if it is on the 4.0 is there a good argument not to study it with 3.x material?
(it can seem a stupid question but I am short on time so I try to maximize productivity)