At the beginning of Pokemon speculation last time, people believed it would be Zoroark. I think that's well founded, and would've been the case had Gen V remained the most recent gen to utilize. People downplay that Zoroark was popular at a time, though being the promotional darling was more important. There were other suggestions throughout the gen as well. Victini towards the beginning and Genesect towards the end, but Zoroark was the constant.
However, then Gen VI was revealed, and expectation shifted. However, there was no Lucario or Zoroark of this gen, so to speak. There was Sylveon, who people dismissed as a plausible candidate. Though I didn't expect her either, frankly, I think she could've worked. But that's neither here nor there. There was also Mega Mewtwo Y, but he was just a Mega Evolution. Very few people believed we'd get just one of the starters, so opinion was mostly that they'd just retain Brawl's cast, and hopefully add Mewtwo back. I imagine there were also a few who believed we'd get a Kalos trainer, though they weren't prominent.
Lucario was seen as the most likely to be cut, but it wasn't a ubiquitous thought. It also decreased when Toon Link, another character often expected to face a possible cut, returned.