Yeah, I think that Fox Sports will be a worthy opponent for ESPN. They have that Rupert Murdoch money backing them, so they aren't going away soon.
They already have long deals with soccer (English Premier League), and UFC, so they will have lots of white eyes starting to switch from ESPN over to them. Their regional sports networks already have deals with NBA, MLB, and NHL, and they will have many NFL type shows on the channel since they have that contract in place with the NFL. They also have a few college conferences locked up (Big East among others)
They are in the works to put bids on the NBA when Turner's contract ends in a few years (2016).
ESPN has already said they are taking Fox Sp. 1 as the biggest threat, and will be suring up their programming starting in August.
If anyone has a chance to compete with ESPN, its Fox Sports 1 (with Fox Sports 2 already planned for next year)