Recently I’ve read the papers describing new Java extensions:
generics, static imports, boxing conversion, enums, and the extended for
loop.

The extensions generally look ok, though in some cases they suffer
a bit from backward compatibility. The real disappointment, though,
is in the papers themselves. I’ve found errors in some of them
(typos, but also more serious problems where the proposed grammar
disagrees with the examples). My general impression is that they
were edited in a rush.