What ever happened to the rule about NEVER EVER throwing a shower for yourself? For any reason--wedding, 10th baby, 1st baby, etc.
I think that if you have a group of friends who want to throw a shower for you then great! It doesn't matter what number of baby it is. There is nothing that says that you have to register for big huge presents. Register for your favorite brand of diapers and wipes, some new books for the baby, and a few new seasonally appropriate clothes. And then very graciously thank everyone for coming and send thank you cards afterwards.
But don't ever throw a shower for yourself! (And for the record, I had a group of friends who threw wonderful showers for all three of my babies.)