Hello,
just found an article on Heise in Germany. Toshiba will release a free Windows Mobile Second Edition for the e800BT and e800WLAN.
Here is the german article:
www.heise.de/newsticker
The article states that the is no way back from the upgrade.
Also it is mentioned using the full resolution 640x480, which is supported by the e800, slows down the system significantly.
Maybe Dell will react to this.