I'll admit I was one of the first to poo-poo this trailer. Admittedly this is one of the few funny characters still on SNL. There aren't many. But it should only work for the few minutes on the show, yet this trailer is pretty funny without giving too much away.
I also love Will Forte and find him very funny, so I'll probably see this barring any further evidence of it sucking.
Here's some other MacGruber shorts: