Hi C.,
Congratulations on the birth of your son. I've never been a big fan of baby wise and feel strongly that babies will guide us with what they need, if we just listen. I've breastfed all three of my children on demand not only because it felt right to me but because it helped get our breatfeeding relationship off to a great start and boosted my supply.
As a first time mom, it was very hard for me to go against what society and the peds dictated about raising babies, breastfeeding, starting solids, sleep patterns, etc. It didn't take me long to find my path and believe me when I say, my babies didn't take advantage of me.
I have breastfed mine on demand, held them when they cried, rocked them to sleep if needed, and never let them CIO. Young babies need the adults take care of their needs and sometimes schedules change...my children were on schedules it's just that I allowed their natural time clocks determine the schedule...they would sleep 5-6 hours at night, sometimes waking sooner or later depending on a growth spurt, and they napped daily.
I wouldn't stress that his schedule is changing, with babies you need to be flexible and you'll enjoy these years so much more if you do.
Also, one of my favorite pediatricians is Dr. William Sears. I highly recommend reading The Baby Book written by Dr. & Martha Sears. They have 9 children(if I remember correctly) and have based their books on their professional education and personal experience. I'm not trying to push my views on you just pointing out there are other ways. Maybe you've already read this book and felt that Baby Wise was more suited for you and your family. If you haven't read it, I do believe it will give you a nice balance and help to guide you as you work on establishing your little ones schedule.
Once again, Congratulations on your healthy baby.
Peace,
J.