With every large card convention comes limited edition VIP/ promotional cards only available at the show. Everyone from Topps to Press Pass (known for NASCAR cards) are there to pass out these little gems. After a little scouring I found a few pics of this years offerings. (Taken from Kit Young's website)
Topps Allen & Ginter is passing out a 6 card set to VIP registrars that includes the great Jackie Robinson (below).
Here is the complete 6 card set that includes Don Larson, Jackie Robinson, Lou Gehrig, Mickey Mantle, Babe Ruth and Johnny Unitas.
Here is a 5 card retro VIP set from Topps designed to look like the 1958 Topps set. The Bob Gibson card below is a fantasy card since he did not have a Topps card in 1958. I guess you can say it's his "rookie card."