I am very happy with the Android phone. Google has hit a big winner here. I understand that several phones are coming out in 2009 with phone with the system on it. I have had a bit of trouble resolving a few issues with T-Mobile tech support (they need more training on this phone) but everything is working now. I put a couple of reviews on a blog I run if your interested in reading more.
http://www.bbqblog.com
I bought it because I like the operating system and the browser is good enough that I don't have to carry around the laptop anymore to fix some things on my servers and web pages when I out of the office. One other thing I trimmed about $45 per month off of my bill when I switched from Verizon.