Hey, I was comparing those two as well. In fact, a purchase of the same drive and Windows 7 HP OEM.
I think the only way Newegg is cheaper if they offer free shipping. The ON taxes kill ya. I think NCIX shipping is usually cheaper, too.... but don't quote me on that.
Another negative for newegg might be UPS doing the shipping but that's another question for the buyer to decide. Also, I read of some complaints of the shippers (I guess, UPS) being a bit too liberal (um, careless?) with the shipments so maybe something to keep in mind? I haven't bought anything from newegg yet so I'm only mentioning what I read on newegg reviews.