Right now, the Google Nexus One is available for T-Mobile. Soon (this spring), it will be coming to Verizon and to Vodafone. By then, I'm sure that the beta version of Epocrates will be thoroughly tested and you'll have access to the full version of Epocrates for Android.
I really like the tri-color clickable trackball on the Nexus One. You'll find this feature on other HTC phones like the Droid Eris. When you're browsing the web, this little trackball makes navigation so user-friendly. BlackBerry users who used to have devices like the Pearl that included a trackball will also like this feature.
Speaking of Verizon, what's going on with the Apple iPhone? Will that smartphone ever make it to Verizon?