Union Square Ventures partner Albert Wenger says he's invested $1.5 million in New York-based cloud-computing startup 10gen, a company founded by some ex-DoubleClickers and a Joost engineer, because there are "some serious issues" with Google's App Engine, a service which allows startups to run applications on Google's servers. Namely, Wenger thinks Google will run the platform's rules to its own competitive advantage. [Union Square Ventures]