Good Luck Chuck 9/21 (not yet rated, most likely R): $6-8m with a total of $15-18 million.
Brothers Solomon 9/7 (Rated R): $5-7m with a total of around $13-16 million.

For now, I give Good Luck Chuck doing better due to "Jessica Alba" (even though not a great box office draw outside of Fantastic Four franchise) a better draw than Will Arnett.

Good Luck Chuck - 13/37
Brothers Solomon - 7/18

I actually think Good Luck Chuck will break out a little.

Good Luck Chuck - $19m/$51m
The Brothers Solomon - $8m/$20m

i think good luck chuck could break out.