I'm glad someone brought this up...
Just for the sake of clarification, if Gmail and Exchange accounts are the only services which push to an Android device, what exactly would this setup achieve? The emails must still be pulled from Yahoo!, correct? They're never pushed form Yahoo!, right?
I'm very interested in purchasing an Incredible within the next few months of its release, and Android's compatibility with Yahoo! email is of great concern because I use my Yahoo! email address as my primary account. I currently use a BlackBerry and the one thing that BlackBerry does well is email. I've been spoiled on the front. From the searching that I've done here on the forums, it seems that there are quite a few issues with Yahoo!'s compatibility with email on Android devices. (Multiple copies of sent items in the sent folder, a bug which prevents you from checking your Yahoo! email via Wi-Fi connection, etc.) Although it's impossible to address any issues specific to the Incredible because the phone hasn't been released, have any of you currently using another Android device been able to use your Yahoo! email account without any major issues?