The following is an official communication from UC Office of the President via the UC system's Facebook page.
Thanks for the feedback. Our new visual approach does not replace the UC seal. The seal is great and we still feel it is an important component of the university’s brand. The UC system did not have another visual identifier and our identity, as a result, wasn't well defined.
The seal will still be used in all formal systemwide communications, including diplomas, regental and presidential communications, and other official documents. This is not a rebranding, but instead the creation of a more coherent, consistent and compelling visual identity in which we preserve the gravitas of the seal. Many of our campuses have limited use of their official seals in similar ways.
You can find out more about how the seal — and the other components of UC’s brand identity — are being used at http://brand.universityofcalifornia.edu.