Who would win?
Clover pros: 1) seems to be impervious to all weaponry. 2) the parasites could make for a good diversion.
3) his arms are huge. thus he could fight G at range
Clover cons: 1) no "powers", no lazers, no fire breath, no nothin 2) Hes just a baby, thus he could get scared and run away... then again, that could just make him go crazier.
Godzilla pros: 1) RADIATION BEAM!!! nuff said 2) impervious to ALL weaponry... no weapons (save the oxygen destroyer) have ever worked 3) He has more experience. Godzilla has earned his title of King of the Monsters.
Godzilla cons: 1) Many powerful monsters hate G's guts. Mothra ( God i hate Mothra), Battra (or is he still dead?), and many others. seeing as how Clover is a baby, the other monsters may pity him and help him out.

My prediction(s): If Clover is to win he would need some help. maybe not at first but after G sees him as a true threat. The monsters that show up could overwhelm Godzilla (it has happened before). Godzilla would ether succumb to the attack (and infuriate fans) or could go to hyper mode and completly obliterate them all.
However, after Clover's allies have lost, G would ether go for the kill (Brutal) or Clover's parent would show up and hand G's ass to him (maybe). think about it. If Clover is just a baby, then just think of how huge the parent would be.
I think that this would make an awesome sequel. : )