We are all looking forward to a hackable phone for which we can write applications. This toolkit allows you to write Java applications for the GPhone.
The Android Developer kit is available for Windows, Linux and OSX. There is also documentation and other useful things at that site.
There are many HTC phones rumored to be arriving with Android in 2008. HTC has really been doing a nice job in the smart phone market lately.
And just to make things interesting Google is offering $10 million in prizes to developers
It is strongly rumored that Android will be released Fall 2008 on an HTC handset.