I know a lot of parents (and many of those who aren't parents, but want to tell people how they should raise their kids) have some unease about the whole Santa thing.
If you want to boil it down, Santa is really lying to your kids for an extended period of years, setting them up for disappointment when they discover that he's not real. But he's also an expression of the magic that's still in the world when you're a kid.
Myself, I have no such ambiguity. I didn't hesitate to start the Santa tradition with my daughter. Everyone is in such a hurry to get kids to grow up and start accepting reality these days, and while there's a certain amount of reality you've got to dose them with in order to keep them safe (the whole "distrust strangers" thing really introduces the notion of other people being unsafe, but unfortunately, a lot of other people *are), there's no need to rob them of a magical world. It's OK, even preferable, when you're a kid, to believe in fairie princesses and dragons and robots and aliens and Santa and the Easter Bunny and all that cool shit.
The trick is, if you *don't* believe this, and you tell your kid there's no Santa, then not only are you robbing your kid of Santa, you are potentially robbing other kids of it as well. Because there is *nothing* that kids who don't believe in Santa love more than spreading that disbelief to others. So while I understand folks who say "I don't want to lie to my children," I can't help but be a bit annoyed that they're making it more difficult for those of us who do want our kids to believe in Santa for a bit longer.
Of course, there are some who can't afford the presents, and have to tell their kids Santa isn't real to avoid disappointing them by having a Santa who can't deliver them the promised presents for being good. I've got sympathy there. But in general, I'm very pro-Santa.