With the legalization of weed happening in a few states, and being considered in quite a few more, it seems that the food industry is ready to attempt to gain some retail growth alongside the legalization measures!
Weed brownies have long been a staple in the Netherlands, but there are many more foods being considered and created in the US as legalization sets fire and spreads through the country.

Snacks that closely resemble snacks that already exist:
Anybody care for a Keef Kat? These snacks hope to closely mimic already popular snacks to get people to enjoy them as something familiar. Products like these can now be purchased legally in four states; retail stores are operating in Colorado and Washington State, and voters recently approved retail sales in Alaska and Oregon, as well.
Are there risks...?
Duh? Of course. There need to be a lot of measure put into place so that kids can't get into these (or animals, or people who aren't allowed, etc.). Not only that, but early (illegal) versions of some of these things were found to have four or more times the level of tetrahydrocannabinol (THC) that is considered to be a safe dose. (Colorado, for instance, set a standard size for an edible serving at no more than 10 mg of THC.) So basically overintoxication is an actual concern here. Still, I'm sure this will be regulated better as the industry grows.
Not only that, but according to the FDCA, foods must not contain additives that the FDA has not approved or that are not "generally recognized as safe." Marijuana arguably fails that standard, but the FDA has given no indication that it will assert its authority.
So I guess we'll see what happens :D