Infants suck to soothe themselves - the action does not necessarily mean he is hungry, but it is one of those few innate abilities (such as breathing and swallowing) that newborns display. He is only one week old - if the pacifier helps him soothe himself to sleep, by all means, give him the binky! He cannot become "addicted" to it yet - so let yourself get some sleep. You will be experiencing the new mommy sleep deprivation boot camp bit for months still, so give yourself and your newborn a break. In fact, most pediatricians and child development professionals agree that giving your newborn a pacifier to suck on while sleeping unattended greatly reduces the rate of SIDS - it is believed that the pacifier in the mouth stimulates the child to suck and, in turn, to breathe. Often, newborns will "forget" to breathe because, well, they are just learning how to do it!
My daughter is just over two, and we are slowly weaning off the binky - she is allowed to have it at nap and bedtime only, and soon, we will make the transition to one binky, and then none.... the only reason I haven't done it sooner is because, well, I think I need her to have that binky more than SHE needs it! She has loved it since she was born, and I have to tell you, its gotten us through some difficult situations (late night emergency room visits, stitches, scraped knees) - I have not allowed its use to hinder her speech (and she is VERY talky) or compromise her teeth. She was sleeping through the night at 8 weeks old (and thats 5-7 hours straight), nursed exceptionally well and gained weight fast - because of the binky, she learned the art of soothing herself at a very young age, and my hubby and I were rewarded with a child that, to this day, can sleep longer and more soundly in conditions that don't seem possible to sleep in! Since he IS so new, it may take him another week or so to get the "hang" of keeping the pacifier in his own mouth, but I would suggest letting him have one for at LEAST a few months until the risk of SIDS has decreased significantly (once a baby can roll over front front to back and back to front, they are capable of rolling themselves out of a situation that would have caused SIDS at a few months younger).