Bob, I don't think these have shipped yet. When I looked at the shipping schedule a couple of days ago, it appears the 4-pack and two 2-packs had slipped to a JAN 2013 delivery.
If you're looking for another CZ option, you might want to keep an eye on the Atlas-O CZ offering... but they're 21" (full scale) and are pretty much at home only on the broadest of curves.
Pros and cons to each. Once Lionel ships them, you'll have the entire set at once. Atlas-O will likely trickle out individual cars over the course of several years. But they're likely the most accurate O-scale model for 3-rail to date.
Although I lean toward the hi-rail look, I'm not a rivet-counter by any stretch of the imagination. So I tend to prefer the 18" cars from Lionel. Best of both worlds, if you will.
David