Its got a lot more going for it than previous technologies. The ones I can come up with off the top of my head...
* Based on OpenGL Embedded which is itself based on OpenGL (a standard that's been around forever)
* Tied to an already hot technology (HTML5 and more specifically the Canvas element)
* Backed by Google and Apple (and because of that able to capitalize on Flash being blocked from the iOS platform)
* Already included in every major browser (except IE9)
* Perhaps most importantly it has the bandwidth to pull of things which previous technologies really didn't.
To put it in one succinct sentence I think it's good technology that's hitting at the right time and that its timing is what sets it apart from previous efforts.
- Backed by Google, Apple and Microsoft (and because of that able to capitalize on Flash being blocked from the iOS platform)
- Already included in every major browser (if you include IE9)
You're right about Google and Apple (and Mozilla are there too) but not Microsoft -- the IE team have explicitly decided to not implement WebGL for IE9, which I think is a mistake. MS seem to be focusing their intention elsewhere, if they come up with a "WebDirect3D" or some kind of Silverlight-based abomination I won't be surprised...
Definitely agree with your other points, though, especially re: Flash.
Silverlight already has some 3D support and the next flash beta will include a full programmable shader pipeline (using CG I think).
So there is some tough competition and with Flash reportedly having a ~97% of the web install base (bar iPhones/iPads which I am still unsure whether that will be an issue or not only time will tell) and a very large developer base it will be interesting to see what will happen.
I'm obviously biased, having put time and effort into this particular one, but I think it may do better than the previous attempts. Two big things that I think help it:
* It's built into all modern browsers, either in production (Chrome) or early-access/beta (Firefox, Safari) with the exception of IE9. And with Chrome Frame, the lack in IE might not be a huge deal.
* It's as low-level as successful APIs like OpenGL and Direct3D (obviously being based on OpenGL). This means that it gives a stable basic API that people can code to that will work across browsers, across platforms. They picked OpenGL ES 2.0 as the baseline because it's the 3D API used on mobile devices, iPhones/iPads and Android devices being the most important. While this low-level nature can make it a bit of a pain to program if you want a higher-level API (like, say, VRML's or X3D's) it also means that people have a solid baseline on which to build higher-level APIs. There are a bunch of good ones already, for example GLGE, SceneJS or SpiderGL.
All previous Web 3D efforts have been complex high-level scene graph APIs. WebGL is different: it simply exposes the underlying hardware acceleration primitives to Javascript in the most direct way imaginable.
OpenGL is an industry standard that already has a proven track record and wide adoption. Furthermore, 3D graphics aren't the only application of OpenGL. Hardware-accelerated 2D graphics (faster and more flexible than Canvas) and general-purpose GPU computing (faster than C on a CPU for many important applications) are both enabled by WebGL.
If IE gets on board, certainly. Otherwise it could turn into the new VRML.
That said, I run a newsletter called JavaScript Weekly and track what items get clicked and which don't. All of the WebGL items I've linked up have done very poorly.. so perhaps the general developer interest isn't there quite yet.
