Like the "Private browsing" mode but you could have many of them, one for Intranet tabs, one for work based research, one for Lunch time browsing, one for "Private browsing".
Also what about bringing:
- Google glears functionality to the native browser: SQL Engine for offline work
- Local network shared caching (especially for stream data aka YouTube)
- Plugin audio and video codecs for native playback (HTML5)
- Quality of Service tagging for smoother browsing
- Telephony and IM integration via gateways/API's
