Apparently, the premiere is going to feature a time jump and open on Elena's 18th birthday, which nicely settles the guardian issue with all parents dead. Well, I was rereading some older episode posts I wrote, and I said this in my thoughts on The Sun Also Rises:
"So, yeah, who's gonna be the guardian for the 17 and 16 year old Elena and Jeremy? I mentioned Alaric above, but that doesn't really make sense. I'm wondering if after the finale issue is resolved, they will have some time pass, even if only a week or two, and Elena will turn 18, and that pretty much will clear it up."
CALLED IT! Hee.