Currently "WikipediA" wordmark at the top of portal page is realized through untranslatable SVG-sprite. While the subtitle "free encyclopedia" is localized. What about localize "WikipediA" wordmark? This is translated and converted into local writing system in most languages (see commons:Category:Localized Wikipedia globe logos, v2 and translatewiki:Special:PrefixIndex/MediaWiki:Wikibase-sitelinks-wikipedia).
Topic on Talk:Wikipedia.org Portal Project
@Kaganer your right that there is a lot of translated logos readily available. However, the difficulty here is that on the wikipedia.org page we use the wordmark separately from the globe logo, and the translated versions all have the globe-logo and the wordmark together.
May be used label from d:Q52