I wouldn't get my hopes up about Dennings:
--She's on a hit show for a competing network. Sure, Melissa McCarthy has hosted twice but she was friends with Kristin Wiig and had movies to push.
--2 Broke Girls kinda sucks. Specifically, the writing is terrible, so it's a poor showcase for how Dennings can play comedy. Which she can do well because I've seen her be funny in movies, but she's trapped into playing a vulgarly overdrawn and obvious character on 2 Broke Girls.
Does general opinion really matter? COUGH Hangover 3, Reindeer Games, Jersey Girl, Alexander, The Internship COUGH. All were movies that didn't sell well critically and/or financially, YET had people host to promote. You could probably add Country Strong and I Love You Phillip Morris to that list.
Oh and Neil Patrick Harris hosted and is on How I Met Your Mother, Which airs on CBS.
Case closed, But I have a feeling your going to ignore this.