Noto Sans has much greater glyph coverage than the overused Open Sans, and renders much better on screens because its weight is slightly heavier.
Metadata Update from @pingou: - Issue tagged with: Artwork, RFE
Are you still looking to do this? Should it be applied to all themes?
Metadata Update from @wombelix: - Issue set to the milestone: 6.0
Metadata Update from @wombelix: - Issue tagged with: easyfix