It's going to be a weekend to inspire Old Guys Who Work Out. That's the prediction of box-office gurus, who figure that The Expendables , starring a group of expended action stars who still sport awesome biceps, will bash all other comers this weekend (and No Doubt prompt an online campaign urging that its director and headliner, Sylvester Stallone, host Saturday Night Live .) They're predicting that the movie will earn around $35-40 million, mostly from young men. Some of their dates, they say, may choose to separate and take in the widely labeled chick flick Eat Pray Love , starring Julia Roberts, which is expected to open with about $20-25 million. Scott Pilgrim vs. the World arrives as the odd man out among the newcomers, destined to open with only about $15-20 million, although it's the only one among the three new films garnering mostly decent reviews.