I disagree with the second suggestion. The value of
certain nodes doesn't erode over time. People who are
discovering these nodes for the first time or who are
using them for the first time should be able to vote on
them. This is especially true because more people are
voting now, so older nodes look undervalued in comparision
to new ones.
Haven't you ever run across a topic you knew nothing about,
and so ignored, only to find yourself later dealing with
it, going back to the related nodes, and finding a great
deal of useful information? Haven't you ever searched
for information on a topic, only to find just what you
needed in a node that was created before you joined?
I want the ability to vote for a good node regardless of its
age. I don't know how many people do go through the
archives looking for interesting old nodes, but I'm one
person who does.