I Just found out that the new plug in for the new Joost.com web site will be, at least at 1st, only for Intel based MAC and Windows PC with the following system requirement:
Windows XP and Vista
System requirements: Windows XP or Vista and one of the following browsers: IE6, IE7, Firefox 2 or Firefox 3.
Mac OS X Intel
System requirements: Mac OS Intel 10.4 or 10.5 and one of the following browsers: Safari, Firefox 2 or Firefox 3.
[...] [fonte] [fonte] [fonte] The Joost: presto in versione web by Luca Palli, unless otherwise expressly stated, is licensed [...]