Last modified: 2005-09-12 22:28:44 UTC
See http://commons.wikimedia.org/wiki/User:Omegatron/sandbox#SVG_rendering. That page shows a 3000px thumbnail of [[Image:223.svg]], which has a "native" size of only 744px. As a result, MediaWiki serves http://upload.wikimedia.org/wikipedia/commons/thumb/3/39/223.svg/744px-223.svg.png for the 3000px thumbnail, and has the browser scale it up! Obviously, the whole point of SVG is that you can scale it arbitrarily large; the "native" size is meaningless and should be ignored.
The maximum scaling size for SVGs is set to whichever is larger of the native size and 1024px by default. Arbitrary scaling is neat, but we do have limited server resources.