According to Boeing total order & delivery figures:
http://www.boeing.com/commercial/orders/totals.html

There are 3 MD-11's yet to be delivered ... and they aren't taking order for them any longer.

Also, I don't believe they are manufacturing MD-90's in Long Beach anymore. The delivery stats show 3 yet to be delivered, but I believe those are from the plant in China building MD-90's (the "trunk liner" as it's called there), not from Long Beach.

What you did see were most likely 717's, not MD-90's. They are kind of hard to tell apart, but the 717 is a good bit smaller. The way I can tell MD-90's is that the engine on them is particularly "fat" ... much bigger than the engines on other DC-9 derived aircraft.