In the novel, the dwarves are losers and Bilbo has to do everything for them. Peter Jackson wants to portray them as heroes ("We are warriors! All of us!") who won the Battle of Azanulbizar.
I somehow doubt we'll see a transition towards the more serious in the later films. Beorn will probably be a killing machine, but
Thranduil (the Dwarf Racist Party King) is already a huge
joke on the interwebs.
As for Gimli, I would initially and without any references say that he's more of a fighter than Thorin's Company. At least in LOTR he's portrayed more like one (heavily armed, openly wearing armour) than any of the Hobbit dwarves. Also when you think of the little encounter with the trolls, Bifur, Bombur and Thorin were the only dwarves to put up a fight.
In the film, everything is extremely unrealistic though. As somebody pointed out in the review thread, after everything that happens in the Goblin Town, you don't really believe Thorin could be hurt so bad so easily.
Oh and speaking of the Uruk-hai, I'm seeing similarities between them and Azog's bunch. Azog seems to me even more built up and vicious than the Uruk-hai, who are supposed to be orcs in perfection.
I guess this just proves what we pretty much knew after the LOTR films - PJ & co twist the plot to serve their purposes even if their changes are irrational.