This just started happening on non-meta sites:
Meta Stack Exchange's logo in the "Featured on Meta" section seems to have been replaced with some site's logo. Mousing over the icon does produce "Meta Stack Exchange" as normal, and the link works.
It even happens in the reputation and inbox dropdowns no matter what site they're visited on:
All the HNQs are showing as being from 3D Printing now:
3D
is at the top. It seems there's a network-wide failure to offset the sheet to show the correct icon.