I visited the http://english.stackexchange.com recently and I couldn't but feel jealous at the nice italic font used over there. At this site, which is much closer to typography we have a slanted font! Can the designers reconsider?
The problem is that there is no italic variant of Lucida Sans.
No, since talic sans-serif fonts are rare and TeX.sx uses a sans-serif font (of which there is no sans-serif variant).