I have written long and nice post about test server, and I got BS.
On short: Test server population was low when server population was low (there wasn't so much difference in waiting time); people didn't want to come when there was no people to play with, so vicious circle continues. Now with higher server population (what you are telling us after 2.0), bots in the game, and PvE MM, there will be more folks on test server.
When was test for 2.0, there was no room on test server. When there was test for German GA or US Republicans, there was enough people for normal games.