Galadriel was one of the most powerful and beautiful Elves in the history of Middle-Earth. When Gimli becomes enamoured with Galadriel it is unexpected and the fact the a Dwarf should become so infatuated with an Elf is played as rare, slightly comic and touching. It's a great character moment for Gimli (and Galadriel as well, as her gift to him helps to show a different side to her character when compared to her lofty scenes with Frodo).
Tauriel is apparently just a guard or soldier in the armies of Mirkwood. It just seems lazy and uninspired to have another Dwarf develop a crush on the only other prominent female Elf in the film series (especially when said crush is held by the only member of the company whose un-dwarven design still fuels my nerd rage).
I have yet to see or hear anything that makes me comfortable with the inclusion of Tauriel. I fear that she may weaken the development of Bilbo as an independent hero, due to her presence in the Mirkwood scenes and a fear I have that she may help Bilbo and the Dwarves escape (we already have Thranduil and Legolas playing antagonistic Mirkwood Elves, which makes me think Tauriel may be used to show a more heroic side to them). Mirkwood is the location where Bilbo really steps up to the plate and becomes a truly valuable asset to the company, fighting a horde of Spiders, evading capture by the Elves and rescuing the Dwarves with a plan he himself conceived, all without the help of Gandalf. If Tauriel is holding his hand, so to speak, during all of this then it will considerably diminish his character's achievements. I know this fear is unfounded at the moment, but Tauriel is clearly a substantial role (otherwise they wouldn't have bothered creating a new character) and apart from the Battle of Five Armies, the scenes in the Elvenking's Halls are the only place where she can get any real exposure and development.