I'd drop Ponson for Gonzalez right away. Gonzalez will get some Ks and nice ratios and has a chance to move into the closer's role if Jose Mesa finally remembers that he's actually Jose Mesa this year. Depending on who you would be dropping for hitters, I would look at Donnelly and Madson after that. They'll both give good ratios and may vulture some wins, though neither is very likely to see any save ops.
I'd hold onto Zambrano and Ortiz for now, see what they can do in the regular season before dumping them. Supposedly the Mets think they can fix a mechanical flaw with Zambrano to improve his control. If that proves true, he could be decent, as he's always gotten Ks and the Mets' improved offense could net him some Ws. Ortiz isn't a guy I would target to draft, but he also isn't a guy I would just drop in a 14-team league. He should at least have enough of name value to possibly include in a trade to upgrade somewhere. See how both of them do, but they are also guys that it won't kill you to cut loose later on if they struggle and someone on the waiver wire emerges and is worth taking a shot on.
"I'm telling ya, he jumped us. Gloves off, stick down, no warning. He challenged the Chiefs. Called us names. But Dave was there."
"Dave's a killer."
"Yeah, Dave's a killer."
"Dave's a mess."