Something that I noted during the recent MoP Developer Q&A was a poll that asked "Excited for Pet Battles?!" The results of the voting shouldn't be taken as concrete stats or seen as a complete representation of the entire WoW and pet collecting community, but I just found it interesting that the 'very excited' vs the 'very not excited' votes were close. 27% to 24%. To top it all off, the more moderate option took the cake with 30% of the votes.
I can't wait to see how the interest will shift and what a future poll with similar or the same options will turn out, once more information and details about pet battles is released.
If you'd like to view the poll, simply go to the Wowheadnews page with the Q&A full transcript, and there should be a large clickable box in one of the sections. Hit replay and you can see the entire session (polls, pictures, and embedded video included).