Are wives still called to be a "help meet" for their husbands? Genesis 2:18(KJV)
  
  And the Lord God said, It is not good that the man should be alone; I
  will make him an help meet for him.


Within the broader Christian tradition, are wives still called to help their husbands in their work for the Lord, such as in the home and in the husband's ministry? (I don't mean that they should be employed at the same job as their husbands.)

From what I see, many wives do not support their husbands' ministry, but either have their own non-overlapping ministry, or simply are not interested in participating for other reasons, such as preferring more worldly pursuits. 

Does the Bible teach elsewhere that this helper role should be a fundamental aspect of being a Christian wife today?
The word for "help meet" means more than just a helper. She was to be his counterpart. This is not limited to just man's ministry, but to everything in his life. She was not to be seen as lesser, or just a helper, but as his divinely appointed co-equal complement. This quote I believe explains it better.


  God Himself gave Adam a companion. He provided “an help meet for
  him”—a helper corresponding to him—one who was fitted to be his
  companion, and who could be one with him in love and sympathy. Eve was
  created from a rib taken from the side of Adam, signifying that she
  was not to control him as the head, nor to be trampled under his feet
  as an inferior, but to stand by his side as an equal, to be loved and
  protected by him. A part of man, bone of his bone, and flesh of his
  flesh, she was his second self; showing the close union and the
  affectionate attachment that should exist in this relation. “For no
  man ever yet hated his own flesh; but nourisheth and cherisheth it.”
  Ephesians 5:29...


"The Faith I Live By" P.251

If you see it from this perspective, she is not limited to only help in man's ministry. They are to have one purpose and work together in every aspect of life. After sin came in, she was to be subject to her husband, but notice that this was as a result of sin. God's original plan was to have her be equal with her husband.