My (very small amount of) experience is, if they're taking the time to respond, you're still in the running. I interviewed for an SRO position with Exelon at the beginning of March and found out last week (they had finally made their decisions) that almost the entire class had been filled with internal candidates. I was contacting my HR rep every couple weeks, which she was ok with, to keep up to date on the progress. I'd say keep checking back about the status. Try giving them a call and leave a message, otherwise I don't know why you haven't gotten a response.