Nullable Types (like in C# 2.0)
Please see this first:
This is a great new feature, which makes database programming much easier. I think that is essential, as the article says.
As a side note, I wish that Java eventually gets full support for value types like int/Integer and string/String. int should be a synonym for Integer and string synonym for String. Comparing strings with == should compare the value, not the object reference. Likewise, comparing Integers with == and != should always compare the value, not the reference.
And I wish that Java had int? type in the future.