User blog comment:Crazylittlefreakgirl/Fairy Tail Official Pairings?/@comment-72.66.31.250-20120517004615/@comment-76.161.172.226-20120517154336

I don't think he particularly had a plan in mind for Lisanna when he brought her back. Hence why she's been largely sidelined since, as he's not sure what to do with her, and most of her natural roles conflict with Lucy and he doesn't want to touch off a big shipping war.

That said, NaLu definitely isn't as canon as people like to think, and it certainly has never been anywhere near as canon as Jellal and Erza. Natsu and Lucy get so much screen time, cover page time, etc together because regardless of romantic status, they're still the main hero and heroine, and partners. You see the same effect at work in Monster Hunter Orage.

Bottom line is that no romantic pairing for Natsu is currently canon.