<p>What are the implications of including a set of visual components released under a <a href="http://www.mozilla.org/MPL/MPL-1.1.html" rel="nofollow noreferrer">Mozilla Public License</a> in a commercial application.</p>

<p>Do I have any obligations?</p>

I've found pretty good analysis on MPL (and others) by Frank Hecker here:
http://hecker.org/writings/setting-up-shop
(search for "Mozilla Public License")
This pretty much sums it up:
For MozPL-ed source code considered as
  a set of source files, modifications
  of the original source files are
  considered to also fall under the
  MozPL, as are new source files
  incorporating extracts from the
  original source files. Such modified
  or new files are required to be
  licensed under the same terms as the
  original files, and in particular must
  be made freely and publicly available
  in source form.
...
Thus an open-source product initially
  released under the MozPL may be
  extended with proprietary code to
  create new proprietary products, as
  long as the proprietary code is
  separate (i.e., in separate files) and
  interacts with the open-source code
  using a defined API.
But as usual, read it carefully and consult your lawyers.