Godparents I don't think they will break the pattern they have shown so far. They have done 6 godparents for each child, 3 from Chris and 3 from Madeleine. 2 family members and 1 friend each.
Leonor:
Tatjana d'abo (chris sister)
Ernst abensberg von truan (chris' brother in law)
Alice Bramford (chris friend)
Victoria (Madeleine's sister)
Patrick Sommerlath (Maddie's maternal cousin)
Louise Gotlieb (Maddie's best friend)
Nicolas:
Natascha abensberg von truan (chris sister)
Henry d'abo (chris brother in law)
Marco Wajselfisz (chris friend)
Prince Carl Philip (Madeleine's brother)
Gustaf Magnuson (Madeleine's paternal cousin)
Katarina von Horn (Madeleine's friend)
New baby I could see since she has already used a cousin from both sides, Madeleine using both her brother and sister in law (Chris used both his brother in laws on mom's side). Hopefully we will see one of Chris' paternal sisters used this time.
possible:
-Prince Daniel (Madeleine brother in law)
-Princess Sofia (Madeleine's sister in law)
-Stefanie, Annalisa or Karen O'Neil (Chris' paternal half sisters)
-maybe one of Chris' nieces or nephews-the nephews might be a bit young (teens but not sure if they usually go with adults)
-friend each of the couple, maybe we will see Chris' best man Cedric finally
Nicolas and Leonor while unusual do have a certain family link. They are variations at least of family names. Leonor is of course a form of Eleanor/a which is a Swedish royal family. Nicolas is a form of Niclas (Desiree's husband). We may see another name that is a more modern version of a family/royal name. Perhaps a more English sounding form, for Chris. The middle names of the kids so far have been family names. Leonor has Lilian for Princess Lilian and Maria for Eva Oneil. Nicolas is named for both grandfathers.
If a girl I think we will see Silvia/Renee to honor the queen finally. Josephine is highly likely. Not only as a middle name of Madeleine, but it is Chris' paternal grandmother's name. Chris' grandmothers were Maria and Josephine, and we have already seen Maria (both Eva and her mother's name).
Princess (first name) Renee Josephine
I could see them using perhaps Alice as a first name, going direct family, for Silvia's mother. Nice English name for Chris. But would be a change for them.
Princess Alice Josephine Renee
boy:
Prince (first name) Christopher Andreas (Andreas for Maddie's godfather)