Adobe has gone on record saying that the flash performance, with Flash Player 10.1, on the Mac will be just as good if not better than flash on Windows.
With support for a broad range of mobile devices, such as smartphones, netbooks, smartbooks and other Internet-connected devices, Flash Player 10.1 allows your content to reach your customers wherever they are.
Flash 10.1 is scheduled to ship in the first half of 2010.