I don't think that we'll be able to access anyone else's game.
When I read the description, I thought it meant that we would create a venue, with a stage in our town and that the new Simport feature would allow us to 'invite' (for want of a better word) a sim, created by a friend, onto that stage to perform for us. We'd get to view how well they sang or performed magic - in other words we'd watch their act - I didn't get the impression that the 'invited' sim would be able to do anything else except to be a guest star in our game.
Currently, unless we share a sim as a 'family' they don't come with any skills. I wonder if it is possible that the Simport will enable sharing of sims, complete with skills and personal inventories? But I'm still inclined to think that all we'll get is an act to watch on our stage.
And, if it is just an act to watch, I'm wondering if we get to customise what the sim does in the act... um. like we train up our sim, customise a set of sequences for their act / choose their song / or whatever, then send them via the Simport to a friend who will watch our sim perform the special act that we've devised. If so, then that could be quite fun and quite creative, rather than just watching a set act over and again, with just the sim looking different.
I also don't believe that the new social aspect will be on Facebook. I wonder if it will be a section that we access from the dashboard or by pressing a button, in game?
It all sounds intriguing and I'm looking forward to finding out more.
Oh and I loved the look of those sort of mermaid like costumes at the start of the video... just going to go back and watch again