I've been vegan for six months or so, so I'm not the guru of it or anything, but I'd really encourage you to go vegan if you're already considering it. It's not like egg-laying hens or milk-producing cows are treated any better, or like those farms are good for the environment.
You really don't need to worry about protein deficiency. When I first read it, this question really made it clear to me: have you ever met or heard about anybody in the developed world having a protein deficiency, at any point in your life? Me neither. Your body stores amino acids for later use, so it is no longer believed that you need to eat complete proteins at every meal. Just eat a variety of foods. You'd do that anyway, just so you don't get bored with your food. "Incomplete" protein foods still have all of the essential amino acids; it's just that one or more of them is present in small amounts. If it came down to it, you could get enough protein by eating large amounts of a single food, even potatoes. More detailed explanation of this, along with super simple example diets that get you more than enough protein here:
http://www.vrg.org/nutrition/protein.htm
I'm probably guilty of overdoing soy, myself. I like fake meat, Gardenburger type stuff. No matter what foods you like and are having a hard time giving up, there are vegan substitutes for it that usually taste good as long as you don't expect them to taste exactly like meat. Soy milk, cheeses made of yeast or cashews, tofu scrambled "eggs," etc.
Omega-3 fatty acids are something you probably should put some thought into. You don't need to eat fish. It is probably true that you won't get as much of these fats in your diet as someone who eats fish, but you'll be fine with flax, hemp, nuts, etc. The "big deal" fatty acids in fish are EPA and DHA. The fish, in turn, get those fatty acids from algae that they eat. If this is a concern for you, algae-derived "fish oil" supplements are available. Minute Maid even sells a pomegranate/blueberry juice with algal DHA in it, and I get that from an ordinary grocery store. Even if you have no ethical problem with eating fish, eating fish obtained by unsustainable fishing practices might be a problem for you.
Vitamin B12 is the biggest thing to worry about, since it's not present in any amount in wheat and so forth. It's found in nutritional yeast, which is used in products like "Macaroni and Chreese" that I think taste good. Soy milks and breakfast cereals are often B12 fortified, and the industrial source for this vitamin B12 is bacterial (like insulin).
If you want to be vegan/vegetarian on principle, DO IT. It's good to live life consistently with your ethical principles (about food or anything else). DO NOT listen to people who try to scare you with how hard it is. It's only annoying in social situations where everyone insists on going to a pizzeria, and that sort of thing. I have no problems feeding myself, and I'm not weak and anemic. I've gotten stronger at the local climbing gym since starting a vegan diet. Carl Lewis, the Olympic track star, is vegan.
Don't let people who eat hot dogs lecture you about nutrition. This guy at work who lives off Panda Express and Little Debbie Oatmeal Cream Pies gives me shit about my diet...