A concept class that extends PyRSS2Gen to permit you to include unescaped CDATA characters in RSS feeds.

PyRSS2GenCDATA.py

# This is insecure, and only here for a proof of concept.  Your mileage may vary.  Et cetra.
import PyRSS2Gen
import datetime

class NoOutput:
    def __init__(self):
        pass
    def publish(self, handler):
        pass

class media_thumbnail:
    """Publish a media:thumbnail element"""
    def __init__(self, url):
        self.url = url
    def publish(self, handler):
        PyRSS2Gen._element(handler, "media:thumbnail", None, {"url": self.url })

class IPhoneRSS2(PyRSS2Gen.RSSItem):
    def __init__(self, **kwargs):
        if 'media_thumbnail' in kwargs:
            self.media_thumbnail = kwargs['media_thumbnail']
            del kwargs['media_thumbnail']
        else:
            self.media_thumbnail = None

        PyRSS2Gen.RSSItem.__init__(self, **kwargs)

    def publish(self, handler):
        self.d1 = self.description
        self.description = NoOutput() #You need to do this since the original class checks for the presence of description
        PyRSS2Gen.RSSItem.publish(self, handler)

    def publish_extensions(self, handler):
        def characters(handler, key, description):
            handler._out.write('<%s>< ![CDATA[%s]]></%s>' % (key, description, key))

        PyRSS2Gen._opt_element(handler, "media_thumbnail", media_thumbnail(self.media_thumbnail))
        characters(handler, "description", self.d1)

# How to use:

rss = PyRSS2Gen.RSS2(
	title = "Example Title",
	link="http://example.com",
	description="Example RSS Output",
	lastBuildDate=datetime.datetime.utcnow(),
	pubDate=datetime.datetime.utcnow(),
	items=[
		IPhoneRSS2(
		title="Item Title",
		description="""<p><b>example</b>text<p><br/>
<p>Where are you going today?</p>

""",
		media_thumbnail = "http://example.com/image.jpg",
		link="http://example.com",
		guid="random_guid_x9129319",
		pubDate=datetime.datetime.now()),
	]
)
rss.rss_attrs["xmlns:media"] = "http://search.yahoo.com/mrss/"
rss.write_xml(open("test.xml", "w"), "utf-8")