The Blog/News tool should be able to pull in one or several external rss/atom feeds on a regular basis, convert new items' text or html to markdown, and create a regular entry in the tool. The 'feedparser' package should be used for parsing feeds. I don't know offhand what package can be used to convert html to markdown.
For the periodic fetching of rss feeds, the tool should expose a paster command via setup.py. Then we can set up a cron job to run it.
Test with both a twitter rss feed, and a wordpress blog feed. Make sure those work well.