I still think this is too little too late especially if Google+ is aimed at people under 30, most of that crowd is mobile and smartphones seem to be the way everyone in that group prefers to communicate not sitting at their desktop computers.

Maybe Baby Boomers will like it over Facebook or not at all for either, if it's aimed at a younger crowd I can't see it working unless as stated it's forced upon people.

With iPads and other tablets and mobile devices becoming more powerful with bigger and better screens I think a stripped down mobile social network app would be the best way to attract attention or a completely different concept.