I played on the RSbots (the Pokemon simulator of choice before Netbattle) for about two years after RS came out. Up until after then, people had a general sense that Swampert, Skarmory, Blissey, etc. would be OU, some were kind of in-between, and others were UU material, but there were no official tier lists.
I went on hiatus for a little over a year after that, and only when I came back did I discover Smogon and found that official tier lists had been established.
So in short, it took about three years (give or take a couple months) for tier lists (at least Smogon's list) to be established for Advance. I don't think it'll take more than a year for DP, but don't hold your breath.