Here's some more details:
Golite Ultralite 1+ Season: 40F rating, 20oz, 3 lengths, $200-$240
GoLite Ultralite 3 Season: 20F rating, 25oz, 3 lengths, $255-$295
Golite Ultra 20: 20F rating (really 25-30F), 19oz, 3 lengths, $225
I would like to see GoLite keep the Ultra 20 and just rename it as the Ultra 30, but I believe it is being dropped as the new Ultralite 3 Season is considered a replacement.