I am a bit like you on this. From my understanding they are going to finance different communities. Each community will have their own SMT to award their users.
If we take musing they will award users using their tokens and not Steem or one of the others like SBD or SP. I don't know what it will be called but let us say it is a musing token.
You earn 100 musing tokens today for answering a few questions. Those tokens will hold a value against Steem so their value will fluctuate like Steem does against Bitcoin. The more Steems value increases the more the token should as well.
I don't know if and how the value will increase but I am sure it will and that may be down to users holding creating a demand.
I believe that SMT's are mainly a sign of hope for the community at the moment. The benefits will be many and varied, but given the current state of the overall market, and STEEM's decline out of the top 50 on coinmarketcap, I think people here on STEEM are looking to SMT's to "save" us.
SMT's will mainly be used by dApps like @steemhunt @actifit @steemmonsters and so on to reward their users and contributors. The one's that are most likely to do well in my opinion are the one's planning both ways to earn the token, and more importantly ways to use them.
> What will be their use case?
Each SMT created will have a different use case. The one's that I have seen with a defined plan for use that makes sense to me are @steemhunt and @actifit.
* HUNT tokens are planned to be useable as I understand it for influence and promotion. Say a company wants to launch a product, and wants Steemhunt users to trial and promote it as part of the product launch. The company would have to buy HUNT tokens on the market to pay for promotions by rewarding reviewers and early adopters. Also, users will be able to spend their HUNT tokens on products or services, or to crowdfund like a HUNT based kickstarter.
* It is planned that AFIT tokens will be able to be used to purchase fitness related products and services. Tokens earnt now could be used in the future for a new fitbit for example.
There are many other potential use cases that will vary from project to project, but these are 2 examples.
During the good times in the crypto market (last year) Tokens on the Etherium network were on of the factors driving up the price of ETH. I think many people in STEEM are hoping for a similar outcome when SMT's finally arrive.
My understanding on how it will help increase the price of STEEM is this: (I could be wrong in my understanding here though so feel free to correct me XD)
Take for example SteemMonsters. a game built on top of the Steem blockchain. All actions/transactions happening in that game are being recorded on the blockchain, from buying a booster pack, opening a card and even battling. All these actions are being put into the blockchain, and as some of us know ALL transactions to the Steem Blockchain will cost some bandwidth or Resource Credits.
In order for a DApp under SMT to fully function, that DApp will need to hodl or own first A LOT of Steem Power and this here is why I think it will likely increase the price of Steem. The more DApps under SMT is developed, the more the demand for Steem is in the market thus increasing it's market value.