In case any of you Nexus One owners are eager to start playing with Froyo today...

http://marakana.com/f...

(attempt at your own risk)

Cheers,
Saša

Caution, the Interwebs indicate that rooted N1's first need to be rolled back.
At any rate, I've tried the manual update from 2.1-Update1 on a pristine N1, and it went through without a hitch. Then I went ahead and installed Adobe Flash 10.1 Beta, just for kicks.

Opinion on app installs on external storage
Installing or moving apps to external storage is handled on an app-by-app basis, in Settings->Applications->Manage Applications.
The ability or preference for installation on external storage needs to be declared in an app's AndroidManifest.xml. This means all apps need to go through at least one update cycle and of course the dev has to pay attention to this new feature. Not all apps are suited for installation on external storage. There's a list of features that stop as soon as the external storage is removed where the apk resides. This list includes alarms, services and app widgets.
Personally, I do not plan to allow external storage in any of my apps, as their footprint is quite small, and I don't feel like spending the time suffering through users finding services or app widgets disappearing. Apps with lots of on-board data, such as games, will hopefully find their way to external storage; such cases will net users a lot of mileage.