Well, someone had to say it :)
Voting a lot sets the base level for votes. If good questions get more votes, we can better discriminate between different levels of quality.
Voting helps sort the best content to the top, but it's also a critical part of community participation in many other ways.
I've placed a few votes, one down vote. I've received a few votes. My profile does not show any reputation changes. On other member profiles, I can see reputation changes.
What's up?
Also heavy use of the voting mechanism is a good motivation to write nice questions and answers for higher reputation. Everybody should vote early and often, this is one step to keep the thing alive.
I would vote more, but I have none left. Maybe we should allow more votes during the private beta?
Vote early, vote often is good. But one should mind the daily reputation cap of 200 pro day. If you want to vote for someone who already reach its cap, wait until tommorow. With about 40 votes a day, there is enough votes to spread the love. :)