i am curious - what are you afraid of? that she will want more tv? that now she will want character stuff? that she will forget imaginative play (by the way i dont buy kids who like characters dont do imaginative play. that's not correct. yes they will act out dora goes on an adventure, but the adventure is their own story, not what they saw on tv. i still call it imaginative play. kids not used to character still introduce their own characters, so i dont really find any difference between character and characterless imaginative play. however some kids DO imaginative plays more than others, and some are far more imaginative than others)?
just coz they are talked to doesnt mean they will get into it. dd's bf in daycare LOVED, loved princesses. dd listened to her and didnt get into princesses till she was almost 5. even then she assessed all the princesses and decided princess fiona was her favourite because she was such a kickass princess :)
now that i have a 10 year old, looking back - in the whole realm of things - it wasnt such a big deal.