I think it could even do better. Best case scenario is it becomes a Mario Kart killer of sorts (I hate the phrase ___ killer) and appeals to all age groups; but the worst case scenario is its too complicated (the track creator, etc.) and people see it as a cheap Mario Kart ripoff.
Realistically I expect it to have a slow start but have great legs. I'd be super happy if it reached 3m like LBP did.