Google acknowledges in its announcement that it will eventually reach out for the enterprise, as well as ISPs and universities.

The company's arguments for the benefit of using hosted applications in lieu of an installed software base aren't really new ones: Going with a hosted app can save you money and reduce the amount of time your IT staff has to spend on maintenance.

"A hosted service like Google Apps for Your Domain eliminates many of the expenses and hassles of maintaining a communications infrastructure, which is welcome relief for many small business owners and IT staffers. Organizations can let Google be the experts in delivering high quality e-mail, messaging, and other Web-based services while they focus on the needs of their users and their day-to-day business," said Dave Girouard, vice president and general manager, enterprise, at Google.

Arguably, the same potential drawbacks to relying on hosted versions of business-critical applications apply: You're at the mercy of the company to stay in business, to remain committed to supporting the product, and to maintain uptime.