Sounds good.

In order to make sure current wikis will work fine (i.e. don't need to update their MediaWiki:Common.css to put the magnify icon to where it was), yet let there be a way to modify the style (when needed) through MediaWiki:Common.css, I suppose this is the best solution:

• The above said "float" style is removed from the <div> tag which contains the magnifiy icon.
• A section is added to the appropriate css file in Common skin, setting the float to right (as is for LTR wikis).
• A similar section s added to another css file in Common skin (I propose common_rtl.css) which sets the float to left (to be suitable for RTL wikis), along with other required changes (setting the text to appear right-aligned, etc).

That idea works "in theory", because (1) common_rtl.css is only loaded with $wgContLang->isRTL() is true, and (2) MediaWiki:Common.css is loaded after both Common skin CSS files, and can add tweaks for bi-directional wikis. However, I'm not sure if it works in act, specifically because I don't see "common_rtl.css" to be loaded on Wikimedia's RTL wikis (and I don't know why), although it seems to be called in Skin.php

Do you think I should touch Skin.php to load that file?

Fixed with a much simpler approach in r30716.