DB> Did anyone every come up with a new packet layout?  

Yes. A whole lot of them. Just look at the FSC's. 

And then there are some which never made it to FSC's/FSP's, I guess.

The only one I know to make it to implementation on a noticeable scale
falls into that category. The Pkt2000 format. However, considering it's a
fairly new one there may still be hope that we'll see an FSP for it.


 DB> Also, who is handling the technical specs for Fidonet now?

The FidoNet Technical Standards Committee (FTSC).

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