Tim,
Here are my views on +1
Impact on SEO
Google open stated that they will consider "+1" as an signal for displaying search results along with many other signals they use to determine a page's ranking and relevancy. Very soon it is going to be available for the users to add it to their site, similar to Facebook like button. The +1 has an influence on crawl and re-crawl of the website.
Impact on Paid Advertising
Needless to say, this is Google's next attempt to beat Facebook's effective advertising after Google Buzz. As of now, the quality scoring is not changing based on +1. Just like Facebook, Google can now monitor all demographic and personal information through "+1" and give benefits to paid advertisers like increasing the CTR based on accumulated +1's and attract the interest of searchers, which leads to ads popularity and lower CPR and higher average rankings.
My Views on It
Spamming this concept is very time consuming as the +1's stick only to your Google circle. Even if a spammer creates thousands of google accounts for increasing the +1 count, he ll be missing the contacts in those accounts. Even if contacts are managed, Google can easily catch the spot manipulation. Though this is restricted to only 5% of users for testing, using this can help our further campaigns.
Your views are appreciated on this.