XML: What it is Not

Not the answer to all the world's problems

verbose: not suitable for low-bandwidth environments
not a particular vocabulary: just a way of defining a vocabulary
doesn't solve the yours/mine/ours vocabulary problem
which just masks the even harder yours/mine/ours modeling problem
all about text or data represented with character strings: no good answers for binary data
some folks busily reinventing all the same bad answers using XML as plumbing