Aston Villa cannot be underestimated anymore but I don’t think they can challenge for the league because they are not so consistent in winning against smaller teams and that could cost them in the long run because consistency is all that matters to challenge for the league.
Aston Villa is impressive, in the last two matches they beat Arsenal and City, and these are championship contenders, so I do not rule out that Aston Villa can to join the championship race. At the moment they are only two points behind Liverpool, but everything will depend on how well they play away games, so far everything is fine in home matches.