My vote would definitely go for the Hiptop, for a few reasons:
1. Java based OS
2. Wozniak is on the team there
3. Smaller, lighter, cooler, neater looking
4. No legacy PC rubbish, no Windows OS!
However, I suspect the Ogo might get a little more support from the marketeers at MS, who will see it as a chance to expand their profit margins just that little bit further.