They now have access to your financials, your location, your search, your email. You've handed the most amazing trove of your business's intelligence over to Google to manage and handle for you.
Generally I trust Google. But, when a company has a fiduciary duty to maximize shareholder value, and more and more corporations start switching over to a Google Apps platform over the next decade. I'd be suprised if Google didn't start to use that huge trove of business intelligence to it's financial advantage.
If Google acquires a company that's in Union Square's portfolio, wouldn't it be silly _not_ to look at what's been going on in Charles River's Google Apps account regarding that company?
That said, I don't agree. Sure its possible, but Google is going to jeopardize its entire business to see what Fred Wilson is emailing his partners? Yeah right.