One of the biggest strikes against Android is the lack of an official, native first-party Microsoft Exchange ActiveSync client (third party support isn't quite as nice). We don't personally use Exchange but we know many folks who know of nothing else. So if you're a big Exchange user you'll be happy to know that the HTC Magic is going to offer Exchange ActiveSync support.
But there's a catch. The HTC Magic needs to be a non "with Google" phone in order to offer Exchange support. In this particular case, The HTC Magic that was seen with Exchange lacks the "with Google" branding and was therefore allowed to load whatever custom build of Android that HTC wanted. For example, the HTC-customized Magic includes better contact integration, more responsive and full featured camera app, and additional home screen widgets that won't be found in "with Google" HTC Magics. This particular Magic will be available in Singapore and most of Asia.
So basically, for Android phones that have the "with Google" branding (check the back of your G1 or Vodafone's Magic) will have to fall in line with certain standards that Google is putting out. The "with Google" branding is simply a carrier decision and though it definitely weakens the power of the device, the carriers get the benefit of name recognition.
We wish it wasn't like this and that we could have the best of both worlds, but we think HTC stands correct on this. We want our phones as full featured as possible!