The new HSK essentially covers the same overall areas of proficiency of Chinese that the old HSK did. However, there are significant differences.
The new HSK is easier than the old HSK. The new HSK contains significantly less words that the old HSK, regardless of the level.
The new HSK’s speaking test is optional. If you want to take the speaking test–which was mandatory for the old HSK–you need to register for it separately.
The new HSK does not have a “zong he” grammar section. The old HSK had a section almost entirely dedicated to grammar. Many students felt this was the hardest part of the test. Even some native Chinese speakers had problems with this section. The new HSK does not test grammar directly.
The new HSK allows typing. The old HSK’s writing section was entirely paper-based. The new HSK allows typing, which means you really don’t need to be able to write characters, so long as you can type Pinyin and recognize the characters that you want to type.
Overall, the new HSK is much more accessible to learners of Chinese.