I've responded to these threads before, but I'm going to do it again, because every time they pop up people continually miss the main issues and just turn it into a "casual vs. tournament" rant.
The predominant view among people on this forum seems to be "I like wavedashing and it should stay exactly the same." THIS IS NOT POSSIBLE. Wavedashing as it is now is a MISTAKE. The developers designed the characters and then wavedashing popped up completely independent from their balancing efforts, having its own random effects on the game. This can't happen again. It's impossible. The developers know about it now. They can't, in good conscience, just ignore it again and hope things work out. They need to consider it. They need to make decisions about it. Regardless of whether or not you are in favor of wavedashing being in Brawl, the fact of the matter is that the developers need to factor it into their work, and that's going to result in some changes, one way or another.
I am going to emphasize this again because it is important. The developers need to worry about wavedashing when they are developing the game, which is a new challenge for them. With things as they are now, some characters (let's say Fox) can do all sorts of crazy and useful things with wavedashing, whereas others (let's say Link) simply can't take advantage of it in the same way. And I think we can all agree that that's one advantage that Fox really didn't need over Link to begin with. For Brawl, it's a safe bet that the developers are going to try to balance Fox and Link better against one another, and the advantages potentially conferred by wavedashing are going to come into play. Similarly, characters like Luigi are currently useless unless you abuse the hell out of the game mechanics. Are the developers going to be okay with this, or should they bring Luigi up to par at the base level?
So, continuing with the developer perspective here, what are their choices? The easiest thing to do is remove wavedashing from the game and balance the characters without worrying about it. They'd have a much more complete grasp of the cast's combo potential and could thus balance it with less unknown factors lurking in the background. And they'd buff characters like Luigi and Ice Climbers so they wouldn't have their wavedash-dependancy anymore. All the characters are equal and the game is balanced (in theory, anyway...they have a lot more than just wavedashing to fix one way or another). The downside? Those who are accustomed to high-level play feel that a layer of complexity has been unjustly removed, which is a totally valid concern. The game is balanced, but the cost might be too great.
Option two. Wavedashing continues to exist, mechanically identical to its current incarnation, and the developers balance around it. Melee's wavedashing elite is happy because their style of play is preserved, and they have a lot more viable characters to play as on top of it. However, now we have a whole new mess of issues. This doesn't change the fact that characters like Bowser and Link suck at wavedashing, so if they're going to be able to compete, they need to be beefed up in other areas. Now we have a situation where Fox and Link are equal in a fight between highly-skilled players...but the Fox player had to work ten times as hard to reach that level of proficiency, because Fox's style of play requires a lot more technical aptitude than Link's. That hardly seems fair. And then there's the non-wavedashing public (who, I hasten to remind you, is the majority by a wide margin). They're now stuck with a poorly-balanced cast...if a wavedashing Fox and a wavedashing Bowser are equal, then a non-wavedashing Bowser is going to beat the living tar out of a non-wavedashing Fox. They feel like the game philosophy that they fell in love with--one which emphasizes skilled application of a small pool of very simple abilities--has been thrown away to cater to the whims of an elite few. And quite frankly, I'd say they had a point.
So, if they remove wavedashing completely, they take some depth and variety away from the game, but if they embrace it as it is now, they throw away the core design philosophy of the series and alienate the larger portion of their audience. This obviously calls for a compromise. My proposition? Drop the whole "air-dodge into the ground before you jump to trick traction into moving you" mess and turn wavedashing (or something similar to it which is more custom-designed for each character rather than working purely off traction) into a basic maneuver with an appropriate control method (diagonal-down while holding L/R is the obvious choice here...almost exactly what it was before but not requiring frame-perfect dexterity). It probably wouldn't be quite as useful as it used to be--it'd have its own animations and everything, which might give it a more fixed distance or tiny amounts lag or something--but its presence in the game would finally be fully justified, it would benefit every level of play, and the developers could integrate it fully into character balance without screwing anybody over.