Just a note that the 10.6.7 update fixes this previously mentioned Dictionary bug in which the Wikipedia section had a scrolling issue:
When you try to scroll down for more info [of a Wikipedia entry within Dictionary] there will be no scroll bars. Likewise if you enlarge your window you will get only white space.
[crarko adds: I tested this, and it works as described. Nice to see noticeable bug fixes in an update.]
Mac OS X Hints
http://hints.macworld.com/article.php?story=20110321214709608