(Video missing)
John Gruber has a post ‘New High-DPI UI Resources in 10.7.3’, which links to various tweets. It may be true that there are new mouse cursor resources in Mac OS X 10.7.3, and that these resources scale well to large sizes. However, the equivalent resources from 10.7.0 to 10.7.2 are also scalable. My video shows some of these cursors on 10.7.2.
Note that these cursors are truly scalable: they look good at all sizes, not just two specific, arbitrary sizes.