Well, if so, it might have been a good idea to involve more of the people who are actually active in Wikipedia's math area. Right now, Toby and I have both stated that we are not too fond of the texvc approach.
I can understand that - after all, you are familiar with TeX and you want to use its maximum power. But from a Wikipedia-wide perspective, we have to keep other factors in mind.
No, people should definitely be able to create math formulas, chess diagrams, chemical structure diagrams, music scores and flow charts in LaTeX, because that's the wiki way: these graphics can then be modified by directly editing the source code
I know LaTeX and I use it for all my written correspondence. That means that I also know how unreadable it can get, even if you have the 500 page Kopka introduction or something similar near your desk. It's possible to do great things with LaTeX, but then, why not have a Python backend with some drawing library, or maybe a POV-Ray backend as well ..
Instead of arbitrarily providing such functionality, we should, for all different types of problems, think carefully what the best tool for the job is. In Maths, TeX/LaTeX is very popular, so it may well be the best tool for the job here. But for music, maybe the recently mentioned GNU Lilypond would be better and easier to learn/use? Basic diagrams might be best handled in SVG or something like that, for plots a gnuplot backend might be nice. And so forth, and so on. Aside from the usability advantage, you also get the geek factor of being able to play with many different toys.
If we do not do this, we force people who want to participate in the wiki process to learn tools that may be suboptimal, even though there may be better and more popular tools for that specific job. From a usability perspective, that's a bad idea. By limiting initially the scope of TeX use, we avoid this usability trap. If it turns out that the music people prefer TeX to Lilypond, we'll send some hired goons to Tomasz and persuade him to include support for the necessary markup in texvc ;-). etc.
Image layout and table support is currently available on Wikipedia with HTML syntax
Yes, but this is suboptimal because only a relatively small subset of Wikipedia users knows HTML, and for those who don't, the HTML syntax is unnecessarily complex. (We also get lots of different table styles because some HTML wizards love to experiment.) That's why we use the wiki syntax instead of HTMl all over the place. But tables are tricky, therefore we haven't implemented them yet (some good proposals exist).
Regards,
Erik