Other than it being double the potty training etc. I would just say make sure you have enough time to spend with both. I do think puppies bond closer with each other when they are at a young age, but there is pros and cons to that.
We have littermate labradors and I can tell you they pick up behaviors from each other, bad and good behaviors. We wouldn't have it any other way, but it's not for everyone. If you think its something you can handle, then I'd say go for it.