Well...
On the one hand, the bucket is really unique (I can't think of another game where you could use buckets as a weapon), and it looks fairly strong. Additionally, it looks like it could ink vertically pretty well, which is a problem I usually have with close-range-type weapons (Rollers, Inkbrushes, Luna Blaster). On the other hand, it looks like the kind of weapon that'll disappoint me when I try it out. Ooh, but if I had a third hand, I'd probably end up liking it after a week or so (that happened with the Octobrush, in that order: good first impression > disliked on release > retried a week later and loved it).
As for the gatling, I've always wondered why that wasn't already in Splatoon. Honestly, I'd expected a gatling-gun-type thing to be added as a Special at some point, kind of as a rapid-fire pinpoint-precision counterpoint to the Inkzooka (if that makes any sense). But apparently it's gonna be a regular weapon, thus not as good as I'd pictured (a bit obvious, most Specials would probably be nerfed as regular weapons). Having said that, this is the weapon that got me excited while I was watching that trailer that had it. I'm hoping it has great range (please be Jet-Squelchery), but if it has great power I'll be fine with it only reaching midrange. Still, it could end up being awful if the windup's too long.
I'll have to see which one ends up a mainstay of my arsenal when they come out (hopefully soon!), but for now I'm more excited about the Gatlink Gun.