Honestly, it looks like they made a list of current Facebook/LinkedIn functionality, dropped the childish annoyances, implemented groupings and are in the proce

Honestly, it looks like they made a list of current Facebook/LinkedIn functionality, dropped the childish annoyances, implemented groupings and are in the process of tying together their other services to fill the gaps that they need not build into this first version of the platform. Like ahh points out, Picasa will have tagging, I'd assume your Google calendar will provide event coordinating at some point in the future and Zynga will provide entertainment to those whose streams don't get a lot of traffic.