9to5Mac has posted a new photograph showing a wave-themed banner with an X in the middle, similar to the iOS 7 banner that was revealed earlier today. The spartan and minimalistic banners are significant change from the style used in previous years, particularly the OS X banner below.
The X appears to use the Helvetica Neue Ultra Light font, an extremely thin variant of Helvetica and the same font as the iOS 7 banner.
Source: Mac Rumours