I know the skin is currently pretty contentious here on Boards. Even I can admit that the theme was an odd choice for Ivern, but upon viewing it I personally think it fits him just fine. I'm really digging the retro basketball look combined with that leaf afro; its very Ivern. That said, he doesn't really have a "dunk" in his kit, so "Dunkmaster" is sort of a misnomer.
While I'm sure he'd be fine at dunking given his height, its really Daisy with her 3 hit passive that's doing any sort of dunking. Ivern is really more of a Point Guard; even in his splash art, he's feeding the ball to Daisy. Excuse my limited understanding of basketball, but I think the point guard position is especially fitting for Ivern: he's the guy supporting the scorer, protecting and making sure the scoring guy gets the ball he needs. So I think "Point Guard Ivern"--or something cooler sounding alluding to a Point Guard's job--is more fitting.
Its the same logic behind why its "Goalkeeper Maokai" vs. "Striker Ezreal": they are playing different roles on the team. They could potentially kick off an entire Basketball skin line much like with a simple name change, much like the soccer(football) skins, creating whole teams of basketball players. This isn't to say no more Dunkmasters; with a huge bevy of suggestions, there is a ton of potential for other Dunkmasters to emerge (**coughcough** _Jarvan_).