Furthermore, while any given species might not have survived from so long ago, life itself should never have died out, if intelligent life was common and abundant. The challenges of surviving that era are such that even we can plausibly imagine being able to meet the challenges in a century, or less if we were concentrating.
It's a poetic idea, but the universe does not look like one in which we are some last dying ember living in the carcass of past giants; it looks like one in which there's little-to-no intelligent life in our past light cone.
The question of why they don't contact us is simple: Prime Directive (http://en.wikipedia.org/wiki/Prime_Directive)
Disclaimer: I'm not a particular fan of Star Trek and bumped into this interesting principle, which I believe makes perfect sense.
The Prime Directive was created to preserve the desired structure of drama on a TV show. It is ludicrous from any other perspective.
And that's not to mention that realistically it would be almost impossible for a civilization to completely hide its presence. For example as humans our radio footprint from TV and radio and satellite broadcasts is spreading out of our solar system. That's going to keep on traveling and I don't see any way that we'd be able to just "erase" that so that no one else would notice it.
"the mind seemed to grow giddy by looking so far into the abyss of time."
and
"The result, therefore, of our present enquiry is, that we find no vestige of a beginning,–no prospect of an end."
What would be rather surprising but yet poetic to me is if we find out that ultimately humans are special: we are special in our solitude, entering the cosmos in a period of declining intelligent life due to the expansion. It would be a strange twist: we get some satisfaction in knowing we are unique in being an unremarkable, irrelevant, isolated civilization.