A growing list of circumstantial evidence suggests Microsoft is preparing BPOS Lite, a small business version of the software company’s SaaS application platform. The move could help Microsoft to (A) provide a migration path from Microsoft Small Business Server while (B) strengthening Microsoft’s competitive hand against Google Apps. But where will channel partners potentially fit in? Here’s some perspective.

The latest BPOS Lite word comes from Mary Jo Foley, who pens the All About Microsoft Blog. Foley hears Microsoft will launch a BPOS Lite cloud productivity suite in late 2010. At the same time, Microsoft’s Stephen Elop in a recent Bloomberg interview downplayed potential B2B SaaS competition with Google.

That’s why I think it’s interesting that Microsoft is prepping BPOS Lite, a scaled-down version of their hosted Business Productivity Online Suite, to go right up against their newfound rivals at the Googleplex. Google Apps deployments certainly aren’t limited to small businesses, but the combination of the familiar Gmail interface and low TCO have made them a hit for companies (or municipal governments) with limited IT budgets.

As Ina Fried notes at Beyond Binary, Microsoft often makes a lot of noise about serving small businesses, but hosted applications (like the versions of Exchange and SharePoint included in BPOS) may let them actually follow through by cutting customer costs.

The big question: Where do partners fit in all this?

As we’ve noted, Channel Chief Allison Watson continues to recommend VARs and MSPs give BPOS and Windows Azure a try. And there are signs that Microsoft will soon more aggressively promote BPOS options to channel-oriented peer groups. I suspect BPOS Lite will play a role in those efforts.

Still, Microsoft Small Business Server has been a lucrative money maker for VARs. Microsoft needs to somehow ensure BPOS Lite offers similar channel opportunities as some small business customers potentially embrace SaaS.

Additional reporting by Joe Panettieri. Sign up for The VAR Guy’s Newsletter; Webcasts and Resource Center; and via RSS; Facebook; Identi.ca; Twitter and VARtweet.