Now just because everyone says it's normal to only go a few hours at a time, which it is, it doesn't mean you can't try a few tricks to get your LO to sleep longer. For instance: swaddling. Swaddling is the best thing since sliced bread in my book. My ds started sleeping through the night at 9 weeks and I believe I owe most of that to swaddling.
Now we got out ds's old miracle blanket and have been swaddling Alexia for the past week and it has been AWESOME. She always goes at least 3 hours now in her first block of sleep at night. Last night she went almost 6 hours....of course I'd had some caffeine yesterday and I couldn't sleep a wink
We also have started a little night time routine which I'm not sure she notices right now but she will eventually and I believe that helps as well. I know the majority of moms here on MDC say a baby won't sleep through the night for a long time but you also have to remember that many parents find this style of parenting because they have a high needs baby and NP/AP is something you tend to fall into with that type of child. So don't be totally discouraged, sometimes you get lucky!