It's quite a bit larger though, so might not get filled up on some of the smaller routes. The737 is a single aisle, the 787 would be a double aisle. Here is a link to some interior layouts- most airliners won't use the seats shown (they'll put in a lot more) but you can see it's a lot taller inside.
http://www.boeing.com/commercial/gallery/787/k63450-06.html
-Craig