See bug 307181 comment 31.
FWIW, it looks bad on Windows as well.
Yeah, overall we should avoid the use of italics on all platforms, since we're not using fonts that have dedicated italicized versions. If emphasis is needed (which it isn't in this particular case), we should use bold instead.
Created attachment 609184 [details] [diff] [review]
The updater informational messages should not be italicized