A quick update on WYSIFTW, my "augmented wikitext" editor. (Please see http://meta.wikimedia.org/wiki/WYSIFTW for details.)
Wikitext support is nearing completion. I added bold/italics a few days ago, and yesterday it got some buttons to apply/remove such markup from a selection. Just a few minutes ago, I finished wikitable support - you can now edit text in table cells, in the same table layout and style you see in the real article (though you cannot alter the table or cell markup itself, add/remove rows, etc., which can later be achieved through buttons in the sidebar or similar).
As of this moment, lists, indentations, <nowiki>, <pre>, and "---" (<hr>) are not supported. These shouldn't be too difficult, compared to the things already done.
I have taken great care to avoid unnecessary changes in the wikitext being introduced through the parsing/unparsing process. I am not 100% successful, but after test-loading dozens of random pages, as well as a few of my standard tests (including [[Paris]] and [[Berlin]]), these events seem to be rare, and do not appear to break valid wiki syntax. If you find a page (it will warn you in the sidebar after parsing), please add it to http://meta.wikimedia.org/wiki/Talk:WYSIFTW#Pages_with_inherent_differences .
The editing components have improved as well, but are far from the usual Word-like capabilities. No cut/copy/paste, and no undo. The former should be easy to do, at least for plain text; the latter will require "recording" of all editing actions, which sounds like work to me :-(
Speed has become an issue. I work with Chrome 10 on a not-too-old iMac, so even behemoths like [[Paris]] are parsed in <20sec. However, I have heard reports about times of >200sec, which is clearly too much (20 sec is as well, IMO). A large chuck of the time seems to come from bold/italics parsing, which can include up to four separate parsing steps in my implementation. There is clearly room for improvement, but I hesitate to optimize until all major features (e.g. lists) are implemented, and I have some standard test pages available. I am also thinking about using Selenium once WYSIFTW is feature-complete (as far as wikitext goes).
There is the question of what browsers/versions to test for. Should I invest large amounts of time optimising performance in Firefox 3, when FF4 will probably be released before WYSIFTW, and everyone and their cousin upgrades? As a one-man-show, I have to think about these things.
Finally, there are, undoubtedly, a large number of bugs hidden in the code. I assume they will be weeded out, given enough eyeballs (testers and developers).
That wasn't as quick as I said in the first line of this mail. OTOH, it's past midnight here (again!), and I'm getting too old for this...
Cheers, Magnus