Has he improved the defence at all? We still have no goalies signed past the end of this season, he really needs to get on that. Would be horrible to go into this summer without any goaltender signed. He's made a few good trades and signings but some of them were later then they should have been. Hendricks for Dubnyk(Dubnyk should have been moved in the off season for a 3rd/4th line vet grinder), Bryzgalov signing(guy was playing in the ECHL while we lost any hopes of the playoffs). This team still has a long way to go and MacT hasnt addressed goaltending or defence long term. Next year isn't looking any brighter for Oiler fans then this year if Mact can't get the defence and goaltending up to at least league average.
He can't fix all the mistakes made previously in a season. Top 6, bottom 6, Centers, 1/2 D, 3/4 D, hell, even 5/6 D, Goaltending. I don't expect him to fix the entire list of issues in a season. But he's already shored up some of those issues with Gordon, Perron, Hendricks, Ference etc.
Maybe you're expecting miracles, but I'm not.