Eurogamer have confirmed (as much as these things are ever confirmed, in that a Sony spokesperson has said so, but another probably says something different ) that the entry level PS3 will be upgradeable wth WiFi and card readin, and the only thing that can't be upgraded is HDMI out.
So we were right in our estimations there.
http://www.eurogamer.net/article.php?article_id=64766"Both configurations will support Bluetooth PS3 controllers. The only non-upgradeable feature of the 20GB configuration will be the HDMI output."
...
According to the spokesperson, Sony plans to release a Wi-Fi adaptor for the 20GB PS3. They're also planning on a separate adaptor that will let you use memory sticks, SD cards and compact flash cards with the machine.
So we were right in our estimations there.