Huge question I know. But is it possible/necessary/poignant to discuss of history in era's? Is their any real need to?
For example; would it not make sense to refer to more specific backgrounds- e.g. After WWII; Following 9/11; As a result of Napoleon's wars; etc.

Or can they frame a wider perspective, and give us a greater historical understanding; as well as helping history buffs in their tendency for ranking their favorites (a pleasure I hope never to lose)?

Given this; lets have a wide discussion on their relevancy, some ones which are confusing, and as a little guide try and make some lose list of one's commonly referred to (which may just highlight their ability to confuse!)

A few that spring to mind-
1) Baby boom
2)Cold War
3) Post colonialism (Africa etc.)

These are all era's i've heard of to discuss the 40 odd years following WWII; and in historical discussion, other than providing a loose rather interesting frame for the given specific discussion, does it not cloud the issue in discussion, and aid bias in discussion. For example; in regard to the post-colonialism of Africa, by constantly referring to it as a post colonial era, do I not push discussion to negative views of the colonial powers, and looking at how they created and make the situations.
But if i talk of the cold war era situation do i not bias the discussion to talking about how them tensions created the new Africa?

Era 124 was cool. But so was Era 247. Or let's discuss Era 91. That was an age!

On second thought, descriptive names for different periods of time might be useful.

Eras and epochs are the creation of humans, and thus inherently arbitrary and subject to bias like any other endeavor. Nevertheless, as suggested, they do have some usefulness in discussing particular sets of time. Their bias is not necessarily a problem as long as someone is aware of the limitations of our styles of date-keeping. Hell, even dating years the way we do is inherently biased toward a Judeo-Christian view of history (the updated "BCE" and "CE" nonsense aside).