Simple answer: YES!
Long answer: Say for example, the Singularity Neko. If you support the campaign at any tier where a Spirit Pet is included in the rewards, then rest assured we'll make those pets permanent. Anything else would be criminal, right!? Many people are asking this because they've played the Closed Beta and have seen how in-game pets are time limited. Permanent goes for any of the in-game items on offer in the Kickstarter campaign.