Three more huge reasons streaming games to PSP wouldn't be a good idea:
- Lower screen resolution (hard/impossible to read text in games running above 480x272 - limits you to PSone games really)
- Streamed video also isn't up to showing little details or very fast motion, imagine that combined with the above
- Control feedback would be cripplingly slow
Maybe if Sony release an updated PSP with 802.11g/a/n WiFi the streaming possibilities would be greater but latency and screen resolution will always be an issue.