Disclaimer, I am not an attorney, you should seek qualified legal advice... We do not require last month rent at our firm because it is not the norm for our market but we inherited a lease that had that provision. As I read the statute, I do not interpret pre-paid rent (ie last month's rent) to be the same as a security deposit. Pre-paid rent and security deposits have very different rules and handling so it would be our position that we do not need to pay interest.
In the case of deposits on utilities/trash I would think you are much closer to and probably are holding a security deposit and you should pay interest if they put you over 1 month of rent.
Regardless of our interpretation, we actually decided to pay interest in the above situation to avoid the potential for legal costs (1 hour with an attorney exceeded the interest), BBB complaint, hours of staff time arguing about it, bad online reviews or any of the other various things that happen when a resident doesn't like your answer.
I will be interested to hear other people's take on the last month being used before eviction.