One of the two latest incidents above (11 June) has just been translated and reported here:
Singapore-bound JAL Dreamliner turns back due to anti-icing system glitch ? Japan Today: Japan News and Discussion
Er... not so fast, the mods have deleted my own splendid translations above.
Go with this one, more official then ...
Edit, the second incident has now been picked up in this article here, but in less detail and accuracy than my translation of yesterday.
ANA Boeing 787 has engine problem before takeoff ? Japan Today: Japan News and Discussion
Edit 2. There were three incidents in the last three days, summarized here:
ANA Dreamliner domestic flight cancelled - Yahoo! Finance UK