In this video, a webmaster from Michigan is inquiring about the possibility of Google offering a keyword rankings report to their users. He surmises that this can be done either through the Webmaster Tools service or through an API, which app makers can utilize. Similar services are currently being provided by scrapers like WebPosition but it would be much better if Google can come up with an official report generator.
Matt Cutts agrees that this is an interesting idea that they could explore in the future. Google does not like scrapers as they consume server bandwidth so this suggestion has some merits. Right now, though, they are held back by resource allocation issues as the engineering team is already taxed. They are focused on other projects that would add features to existing services like Fetch as Googlebot, Malware Details, and ignoring URL parameters which important as well.
Webmaster Tools continues to be improved and there are a few alternatives already in place that can show keyword positioning on a limited basis. These might get expanded in the future towards an in-depth reporting tool but there are currently no concrete plans to do so.