I'd be surprised if the game didn't do something special for Argonian dragon-borns, I mean someone would have to comment on how ironic it is
IIRC, in Morrowind they commented on it if you were an Argonian Nerevarine.
I would like more flavor dialog given depending on your gender and race in general, not just main quest/dragonborn-related. Todd mentioned factions acting differently depending on your race, so I hope to see quite a bit of it.