Regarding the implementation of this featurethis feature trialling here on meta.
I think the 'in question list notification bar' is a nice feature, however when there are questions with new activity this also prefixes the number of new questions before the title element of the page. I.e.
Meta Stack Overflow
becomes
(1) Meta Stack Overflow
Perhaps it is just because I am so used to Facebook, but to me it makes more sense to have such indicators in titles only when content is directly related to the user.
The feature announcementfeature announcement says that this feature also includes live updating of notifications that would appear in the inbox - this seems perfect for the numerical count in the title, however having every single updated question appearing in tabs on high activity sites would be distracting and would draw attention away from the benefits of these two requests (AA and BB) for title notifications to be displayed similarly to how they are on Facebook.