I got this from Aya Hirano Q&A - Otakon 2012
Audience: How do you feel about the possibility of [Fairy Tail's] Natsu and Lucy getting together romantically?
Hirano: I'd really like to know that myself really! This is a story I heard from [creator] Mashima-san: when it comes to creating a relationship among the main characters of a series, creators have a hard time deciding which direction to go with said relationships. Although many fans claim they want to see a relationship between Natsu and Lucy, others would prefer to see Lucy with Leo. What do you think?
Audience: Lucy and Natsu, definitely.
Hirano: Have you gotten to see any of the footage from the recent movie? There's a shot from the movie where Natsu embraces Lucy in tears and Mashima really liked that particular shot from the movie. I hope you have the opportunity to see it for yourself.
EVEN LUCY'S SEIYUU SUPPORT NALU AND MASHIMA-SENSEI TOO!!! SO NALU IS CANON!!!
YEAH NALU ROCKS!!