Sonic a system seller.
In all seriousness, a big no. The best selling Sonic titles are the Olympic Games ones with Mario, and excluding those the best selling recent Sonic title managed just over two and a half million units. Lost World will help move units, certainly, but it won't turn the Wii U from failing into a success.
It probably doesn't help that Lost World looks very similar to the recent 3D Mario titles.
for me, that is the reason of its [modest] sucess.