If I'm interpreting this right, then "light accounts" are essentially just wallet addresses which represent an interface to the blockchain – but the implication is that they won't be able to do significant transactions.
The immediate and obvious problem is that every transaction that is useful and interacts with the blockchain requires the ability to write to the blockchain, and if you can write to the blockchain as a user, you're a full user.
Unless this system of account differentiation is a backdoor way of pushing access restriction algorithms into the blockchain itself, which goes against a lot of the basic premises of the Steem blockchain, I don't see how we can have two classes of users with one having a username and one without. As it stands, the username is just another data field associated with what's effectively a wallet entry, so the idea of "light accounts" in the architecture that's currently implemented is actively nonsensical.
Like so many of the Steemit Inc. press releases, this is ambitious in ideas of those ideas themselves don't make a lot of sense.
Much like this obsession with the idea that Communities and SMTs are somehow interlinked and entwined when they are very distinct conceptual and interface underpinnings, this amount of handwaving in public is the very opposite of reassuring.
Agreed that Communities and SMTs are technically not interlinked, but I do think that Communities provide a comprehensible proof of concept for SMTs. Almost any effective token system will be part of a "community" of some kind. So while, Communities and SMTs are technically distinct, I do believe that Communities will have a very compelling implementation of SMTs that will be broadly comprehensible to a wide variety of people. Thanks for this very thoughtful comment.
AFAIK light accounts would be wallet addresses that can send and receive tokens and nothing more. This is the only implementation I've heard actively discussed with our blockchain devs and they were not at all under the impression that it is nonsensical. An implementation of light accounts is definitely possible, not difficult even, and in high demand by every 3rd party app developer we have discussed this idea with.
Light accounts are not something we believe we need for steemit.com, but Steem is about far more than steemit.com now and we want to make sure that the Steem blockchain is the best protocol for developers. So we are eager to integrate any feedback from them that we can, as long as it has the support of the larger community and Witnesses.
Start with communities first, that's easier to understand for the end user.
"Communities are like a subreddit, but with the difference that the moderator(s) can monetize their efforts curating quality content".
Then bring SMTs, once communities are big enough they could find usage in a token rewarding their users in whatever way they find contributing.