Not that I'd mind seeing Steve Carell play a reptile (Over the Hedge 2: Verne and Hammy switch bodies?), but that's not what this movie is about, and the poster conveys the wrong concept. It's supposed to be "lonely guy who can't even get motivated to lift his depressed head up off his breakfast", but what it really looks like is "strange Lizard-Man from another world with habits different from our own; he sleeps on syrupy foods. Oh dear, he sees us; don't make any sudden moves!"
I think the fact that we're seeing his face square on is also unsettling. At least his hair isn't symmetrical, like, say, Bob from ReBoot.