New tennis shoes, will they stretch out?

If they have a leather upper, leather does stretch out. You can spray them with some water and put newspaper down the toes and keep shoving in lots of newspaper. As they dry the newspaper should hold them to the larger size. You have to keep putting in more newspaper so they don't shrink.

They might stretch a little, especially if they are made out of leather on top like the previous poster said.

Some shoes stores might also stretch them for you (they're all equipped with shoe stretches in the back somewhere).

if it's a tennis shoe then I assume you mean it's a leather upper (vs a running shoe which is mostly nylon).... the leather will stretch over time, but only a slight bit with normal wear... do what PP said with the water & newspaper and it will help stretch them out a bit.

There are something like 500 ways to lace a shoe and they are all for different reasons. I lace my running shoes different than my hiking shoes and I even lace my hiking shoes different for when I am climbing up a mountain than when I am going down.

Here's a web-site that you can try a few lacing techniques. If I were you, I wouldn't wait for the shoe to stretch, I would lace differently. Maybe try the "Narrow Heel, Wide Forefoot" to give your toe box more space.
http://walking.about.com/cs/shoecare/l/aa120600b.htm

Nope.

I wouldn't count on too much stretching. You may need to go up half a size. Our feet do change, even if our weight doesn't. You ought to try going to a running store or other specialty store and get fitted for the proper shoes.

They will probably strach out a little but not too much.

Nope.