The idea seems very interesting, but the non-free aspect of this seems likely to limit its uptake. I cannot install a version of this for small-scale, personal, or not-for-profit needs other than using a non-durable VM that saves state only when suspended. Even if I buy into the Datomic pricing model and that pricing is not prohibitive, I am still bound to Amazon's pricing model (though hopefully that will expand over time to other cloud services to prevent vendor lock-in).
I think Rich & the gang need to focus on a niche market for now as this technology matures. I expect they will work with a handful of enterprise clients for now but roll out "convenience features" in the future (i.e. easy to use and inexpensive hosting for smaller customers.)
Certainly that's one approach. The one that seems more likely to generate widespread use is to put a tool in the hands of lots of developers, making it easy for more people to get involved and for unexpected uses to happen (e.g. MySQL v Oracle - though I'm not suggesting that the cost scales are equivalent here, it's merely the first example that comes to mind).
Rich & co. have historically been more interested in being correct than being popular, especially at the early stages. I would expect to see more components show up fairly quickly, but not before they're ready for use.
