We’d love to integrate with Mint, but the decision is mostly on Mint’s side. If you’d like Mint to add Splitwise, you can let them know in the comments here:JR commented
I'm interested in this too! Mint is super useful for figuring out where your money is going but it would be even more powerful (and conversely, Splitwise would be even cooler) if they could interface together. Right now it seems like I'm spending a ridiculous amount on groceries, but it's actually split between 3 people.
Thanks for your consideration!