Congratulations 🙂

Cloth diapers, diaper pins, baby powder, baby wipes - they can always be used for other things

And loads of patience

Extra clothes are always handy. Not just for your son, for you too. Kids seem to puke on you just as you are walking out the door. They spill everything. They jump in puddles with no regard to the wind chill factor.

A mattress protector if you plan on bugging out.

Balloons keep my toddler entertained for hours. They are light and small perfect for a BOB.

I’ll second the vote for cloth diapers. Even if you don’t plan on using cloth diapers look on Kijiji for some. The used ones can be found fairly cheap. (if your squeamish about used clothes just tell yourself that this is for emergency use only.) Using them during the day will extend your supply of the disposables. Keep them around after toilet training is done as they will make great bartering items. Don't forget the rubber pants.

Have some recipes for herbal / traditional remedies printed out. It could prove useful in a short term “situation”. It could also keep your stockpile stocked when other parents are in need of medicine.
We thought we had lots of gripe water on hand till we started introducing food. Thanksgiving Day we realized that we were about to run out. Instead of a 45 minute drive to the 24 hour pharmacy we found an online recipe for gripe water. It ended up working as well as the store bought stuff (sorry it’s at home and I’m at work.)

Whiskey, has been used traditionally for teething. I’m not going to recommend it for a non survival situation but this is how the elders of my family say it was used in the past.
Step 1: Pour a shot of whiskey
Step 2: Dip your finger in the whiskey.
Step 3: Rub your finger on the gums
Step 4: Drink remainder of the shot.

First of all, congratulations on the new arrival.
I would suggest checking online for all the Canadian baby product companies such as Johnson & Johnson, Heinz baby, etc.
They all have a promotional program and will send you products like formula and tons of coupons.
We breast fed our babies, but having some formula in storage can, and probably will, come in handy...and the sample sizes they send are perfect for bug out bags!
One coupon I got when my little ones were born was a coupon for one free product from Johnson & Johnson, which we used to buy a multi pack of Peneton diaper rash cream...look for the pack with 3 different sized cans in it...this is by far the best use of that coupon!
In a few months you will be starting him on real food...start gathering jars now, as they come on sale and also, look at making your own (squash was a favorite of my little ones and freeze it in ice cube trays!
Also, if you are pumping milk, it can be frozen for up to a year in a deep freezer...just don't use the microwave to thaw or reheat it.
Always think ahead for clothing...many stores such as walmart will have great deals on summer cloths right now and winter clothing in the spring!
All the best for you and your new bundle of joy...and TRY to get some sleep!

Congratulations! Good for you for thinking ahead of your baby's needs.
I hope you are breastfeeding because even in calm times, it's the best for babies.
As for more prepping supplies, I'd suggest you buy some cotton flannellette - like 10 meters - and keep it for making plain, rectangular diapers. Also, as suggested, regular rubber pants (1/2 dozen in each size) and metal diaper pins. The flannel can also be used for other things..... Extra clothes in various sizes also a good idea.
Babies start solids around 6 months old - regular people food is best. Home made. Mashed up at first. Or ground up in a baby food grinder. Like Denob said, alot of it can be frozen in ice cube trays for use later.
Avoid formula samples - in fact these companies violate the World Health Organization's Code on the Marketing of Breast Milk Substitutes.
Babies are the easiest to Prep for - their needs are simple: food, warmth, love. 🙂

I would also suggest powedered milk just in case the formula runs out.....

Making your own baby food is supper easy and frugal. We use a magic bullet at home and this when we go out. http://www.amazon.ca/Munchkin-13701-Baby-Grinder-Colors/dp/B000GB0NZA/ref=sr_1_1?ie=UTF8&qid=1357277878&sr=8-1
It’s only good for soft food in baby sized portions.

Men ! How much thankful I am for those answers !

We already have 20 Big milk formula cans, (got them for 2$ instead of 25 $ !) but my wife is planning on keeping the baby on breatfeeding.

@ Prepperpie: Best advice of all ! Thanks guys, it's really appreciated !

Just a mention about formula et al...
Yes, I agree that breast feeding and home made baby food is best...no arguments.
However, for a bug out bag or other emergency kit, I have always kept some formula, cereal and (gasp) commercial baby food on hand.
Contrary to some beliefs, this is not poison for your infant, rather a great way to be prepared for emergencies.
Feed the most natural and nutritious foods to your infant but have backup in case you need it.
During a disaster you may find yourself without mom or her milk, so keep some formula handy.
Also, consider that you may be without electricity for a while and jarred commercial food and instant cereals will come in handy!

Just little note.I was born in a little village in Europe that time no electricity no disposable diapers , no baby food,no cereal (still would not eat it) no running water just

very basics.Somehow I had very happy childhood and was healthy. The very basic foods in case of emergency will do nicely. I would just make sure I am not in the city.
Henry