the sessions at sessions.visitmix.com for mix07 have been updated a bit. some have included the slide decks for download, but a lot have also been updated so that you can choose the play option and get the video of the presenter side-by-side with the powerpoint. it is an updated silverlight player, which also has chapter indexes (rollover the video) to fast-forward to points.
anyhow, if you haven't seen any of them yet, or want to review, the player now really makes you feel like you are there!