Matt Cutts announced yesterday, that the Google Sitemap tool will start notifying some webmasters of penalties regarding to the Google quality guidelines . Those owners can issue reinclusion requests then directly from the tool.

But Matt also points out that he doesn't want the typical scraper and spam sites to issue reinclusion requests, as it's obvious that those low quality sites won't find their way back into the Google index.

Also there's a lot more changed in the tool, described in Google's Sitemap blog

• Indexing snapshot – a new Summary page provides a quick snapshot about the state of your site, including if site is in the index, when Googlebot last crawled the home page, if some pages of the site are partially indexed, etc.
• Notification of violations of the webmaster quality guidelines or the general webmaster guidelines