This is only a valve, which is not a very complicated piece of body. It is important, however, mainly because it's not a mechanical or an animal valve (which also seem to do rather well). They need to work a bit more in order to get the valve to the state where the body will maintain and repair it, though. Still, it's quite an interesting breakthrough; this whole scaffolding concept is paying dividends.
People should still take excellent care of their bodies. Firstly, while some people have valve problems with their heart, the majority of people (who abuse their bodies) do not - so the abuse is unlikely to be repaired with this technology. As well, everyone will likely (eventually) need some variant of this technology, but delaying your need is still the best strategy.
This research, specifically, did not use ESC, but they surely used data received from ESC studies. Eventually we'll want cloned cells anyway.