I have seen enough of what happens when coins are stored on an exchange of any kind. Interest on such accounts sounds really great and might indicate a move towards general acceptance. However; what good would a few interest points be if the coins disappear? I want to learn about how they are going to be secured beyond how the normal exchanges have gone over the years. Its tough to imagine sleeping well at night with 100 coins (example only) sitting on an exchange. If you are only storing 1 or 2 the interest would be "pennies.
People are blinded by their own greed and will grab opportunities like these with both hands without hesitation. I personally would never ever hand over my coins to an entity in return for a few percent (or whatever else their rate might be) annually. I like how Bitcoin gives me the opportunity to be in full control of my wealth -- it's sad that not everyone appreciates it in the same way as I do....