I still think it's in D3s favour. Wario can avoid the CG pretty well, yes, and he can camp like a ***** in the air but D3 still has many advantages. I'm not sure but I
think D3s utilt beats Warios dair ... I can't imagine it being the other way round. This makes it very hard to approach D3 ... it's basically a guessing game between bite, grab and dair (everything else
will get grabbed) and he can beat all of them if he predicts it right...and as you know one mistake = a CG, which really hurts Wario.
Wario has advantages offstage ... D3s tiny jumps make him an easy target for Wariocides ... unless he uses upB, which you can fart/clap him out of. Small platforms are in general very helpful in this match-up as they drastically increase Wario's room for error so your main strategy will be camping in the air/on platforms and getting D3 offstage asap.
The biggest problem with this match-up is that D3 has the advantage on the starter stage. Assuming we use the stage striking system it's possible for the D3 player to strike Lylat Cruise and Battlefield, which are the only neutrals, where Wario wins. All the other neutrals are in D3s favour, which means that the first game of a set will always be in D3s favour - he will get to play either on Smashville or Yoshis (assuming FD is a guaranteed ban). After D3 wins the first game it's really hard for Wario to win the set because no matter which stage you ban, there are still at least two stages in D3s favour (Wario has Brinstar and Rainbow Cruise but D3 will probably ban Brinstar): FD, Yoshi's, Smashville and Halberd are all in D3s favour and you can only ban one of them, which leaves D3 with 2 good CP stages (one stage ban + DSR) and he's already more likely to win on the starter stage.
So while it
is actually a rather close match-up in a realistic tournament scenario D3 has the advantage because he has slightly better chances to win on the starter stage. The match-up itself is probably 55/45 in D3s favour but in the context of a real tournament it's 6/4 D3s favour.