Veni. Vidi. Pwni. My iPhone has been updated to 2.0-pwnage, I have installed Open SSH and successfully run programs outside the official Apple boundaries. Without getting into details (I hope to do a live chat tomorrow, along with several other developers), I'd rate the new 2.0 Pwnage software as "for dedicated hackers only".
If you're a casual jailbreaker, or looking to simply unlock your iPhone, you probably want to wait for another week for the bugs to be ironed out of the system and the software to become more stable. The iPhone dev team have done a fabulous job as a first approach -- especially under the huge pressure and time constraints they've been subjected to -- but it's still not "ready for Grandma".
Be aware that a 3G unlock is not part of the current pwnage tool. You can still unlock first generation iPhones though. Jailbreak supports every platform: 3G, 1st Gen and iPod touches.
I'm heading off to bed right now so I've only had a few hours to play. 2.0 from the command line seems both slow and clunky, with a noticeable lag after running even just an "ls" command. In contrast, Applications run more sprightly. (Sprightlier?) They launch quickly and in the case of AppFlow (which was rejected from AppStore) with peppier interface interaction.
The Cydia software, a 2.0-ready Installer.app alternative, seems solid. I had no problems downloading OpenSSH and getting it going. Cydia provides several system optimization features that allow you to relocate space-consuming elements from the limited system partition into the more open user partition. Cydia assumes a more command-line friendly audience than Installer.app did and many of its features are best accessed from the shell.
All in all, it's nice to finally be back home on the phone.