What is the exact use-case you are considering?
Lightweight, name-only resolvers for DNS. I'm not sure if the "name only" part has the same ramifications for BitShares as Namecoin, but since purchasing a domain destroys the currency in both models I'm assuming that it means that a BitShares name resolver will not need to worry about double spends either.
Is it not sufficient to receive a signed statement from a quorum of delegates for the particular data that you are interested in?
I remember Bytemaster posting that every 101 blocks (1 per delegate, thats just over 15 minutes) acted like a snapshot. Would this be similar to a 'meta-block' that you are talking about? At ~15 minutes each it would be similar to Namecoin.
Like I said, I posted this because a few things didn't make sense. When I asked around about the BitShares lightweight client I got the impression that it was a trusted server model ... which I didn't understand given that you could rely on a quorum.
While a lightweight client wouldn't want to have to tally the votes to figure out who a valid delegate is, I would assume that you could bootstrap new delegates by including a proof of some kind in each block.
Sorry for the basic questions. I did some light googling, but I didn't see much on BitShares specific lightweight clients. Is there a blog article I'm missing?