Heads-up -- incompatible changes coming

[Brian Goetz]

> 1) Do these changes only make those classes compiled with -target=1.8 incompatible, or do they make even those classes compiled -target=1.6 with the JDK8 compiler incompatible?

 > 2) Do these changes only make those classes containing lambdas and/or 
method references incompatible, or do they also make even classes 
without lambdas/references incompatible?

Only those compiled with -target=1.8 and which use Java 8 language 
features (lambdas or default methods).  The latter rules out any other 
target.