Dymero - 5:48 pm on Mar 7, 2013 (gmt 0)
As with any other HTML element that doubles as a ranking factor, I use either a "does this improve the user experience" or "does this make sense to the context" test when deciding whether to apply the tag.
Bold is still a good tag for inline emphasis, especially on lists, in order to make the items stand out from a wall of unstyled text. It also is good when you feel it necessary to emphasize some point within a paragraph.
If it doesn't make sense to use bold, I don't. I once did, however, but then I realized I was overusing it to the point of making some paragraphs difficult to read.
In short, if bolding the keyword fulfills the primary purpose of improving the user experience or making a point, use it. Otherwise, do not use it.
Addition: Wading into the <strong> vs <b> discussion, I still like <strong> as it's more generic and structural tag than <b>, and for years was actually the recommended tag to use, for this reason.