[daeron]

If they do have powers, why don't they use them. Especially those in Rivendell. They never took part in the third age. And I would like an other answer than "the time of the elves is over. The age of Men has come".

Another interesting thing noted in a letter by Tolkien is that he considers Imladris to be 'not a place of action but of reflection'.
quote
'Elrond symbolises throughout ancient wisdom and his house represents lore- the preservation in reverant memory of all that is goodwise and beautiful'
unquote

As he says, in the Hobbit they continue on thier journey and in Lotr the embark on a whole new quest. It was also where the last Alliance was gathered of a while.