I don't know, I think they wanted that Google money so much they didn't bother! It might have been in the cards, but perhaps Google beat them to the punch and evaporated their desire to create a search engine. Search engines are likely not a business that Apple wants to get too involved in as well, that's something to consider. Sometimes it's better to use what is already out there and not sink too much capital in something so uncertain. I doubt Apple would've seen a serious amount of success with Google being the top dog in search.