Ashar-
Wikipedia being NPOV I don't think we should enter the war. Moreover saying "this site is best seen with firefox / opera" will just mean to IE users that we are lazy webmasters that didn't want to put any effort in supporting multi browsers (which is false, ask gwicke about css tweaking).
Agreed. However, we should prominently state that Wikimedia is best viewed using a browser that supports web standards A, B, C and D. We could then have an information page (table) that shows which browser supports which standards.
The problem with the browser monopoly is that Microsoft can exercise control over standards. It is this control which matters to us and to everyone else, and making people aware of that fact is perfectly fair and neutral. We should give our readers the necessary information to take control. As long as Microsoft supports all these standards, everything is fine and they will have an "X" in all the table columns.
In the near future, SVG should be one of these standards - as soon as it becomes part of the mainline builds for Firefox and Mozilla. SVG is really important to enable things like animations (without non-scalable and 256- color limited GIFs) and interactive timelines. The current timelines are nice, but SVG makes them zoomable and adds potential for other features which you find in timeline systems of CD-ROM encyclopedias. Note that basic SVGs are already generated, if you view the image for a timeline you can substitute ".png" in the URL with ".svg".
XForms may also provide us with some benefits, although that is probably of more interest to Wikidata where form entry verification is desirable. Switching to full XHTML will be important if we ever want to add WYSIWYG support, as it will enable us to convert back and forth between wiki- syntax and XHTML.
I have no idea what Microsoft's long term plans are for these standards. See, I'm perfectly neutral. ;-)
Regards,
Erik