Well, I believe that JPG is the most commonly used for Wikipedia; PNG is just there in case of making JPG copies to surpass this copy. --George Ho (talk) 15:49, 9 May 2012 (UTC)[reply]
Oppose After thinking this over for a while, I think the lossless PNG is preferable. Commons:File types indicates that PNG is preferred due to its lossless nature, but that due to techincal limitations, we sometimes need to host a JPG also. In cases where we have both, I think the PNG, as the preferred format, should be the VI, since eventually the technical limitations might change and then the lossy JPG would no longer be needed. cmadler (talk) 14:03, 14 May 2012 (UTC)[reply]