I'm agree with you Chilly. If this person was in any way involved with the death of Caylee,the Anthony family would be screaming his name on rooftops. They may want to protect their immediate family,but no way would they be protecting anyone else. Not even Caylees' father.I don't think he's involved,so know need to know who he is,but why they are so fiercely keeping him a secret is puzzling.
I agree Caylee's father's name does little for the State's case, it's only of use to the defense. A possible solution to this puzzle goes to the topic of potential "bombshells".
My legal entanglements have only been civil, but if criminal cases are anything like civil-- discovery is reciprocal. I believe the discovery time-line is a bit later for defense, so that they can respond to the State's evidence and depose the State's witnesses etc.
If I've learned anything about responding to discovery: it's that you don't have to provide discovery for things you don't know, that the opposing side doesn't ask for, or can be argued is an undue burden to you. But if you can argue that you just recently uncovered this information you can, with the judges permission, get it into the trial later in the time-line. This favors a strategy on both sides to delay the finding that you really "know" something until closer to trial, to limit the amount of time that the opposing side has to prepare a counter-strategy.
In this case it seems in the defense's interest not to "know for certain" Caylee's father until later in discovery, to give them build time for that bus they'll throw him under. And of course, less time for the State to kick the tires on that "bus" for shoddy workmanship. Public opinion of Casey's love-life is pretty low anyway, so there's a plausible argument that Casey doesn't know who the father was, or going way way out on that limb, they could argue they didn't trust her to tell them the truth on the subject. Thereby providing cover for a potential future "bombshell". The same can be said on the State's side for "bombshells" from reports on forensic evidence. CSI on TV notwithstanding, they can argue that good and complete forensic analysis and reporting takes significant amounts of time.
It's not exactly Perry Mason, but IIRC Perry was a defense attorney, and not a State Attorney. Maybe I watch too much TV, but it seems judges tend to favor "bombshells" for the defense and less so for the prosecution.
There's a bit less "Sunshine" of this sort in CA, but it sure seemed to me that Mark Fuhrman's recordings of racial epithets were a late discovery in the original OJ trial. Whether this was reality or not, it sure sounded like a surprise bombshell to me.