I just read an article on infoSync World where they conducted a survey of readers to find out what are the most vital aspects of a business phone. The number one feature was 3G connectivity, which is still something just rolling out here in the U.S. The second feature was push email support, followed by thumb keyboards, talk time, and Office document viewing. infoSync World listed 3 devices that satisfy these desired features with the HTC TyTN (aka HTC Hermes), Sony Ericsson M600i, and Nokia E61. Neither the HTC TyTN or SE M600i are yet available and won't be released until July starting in Europe.
After using a Treo 650 for over a year, I recently discovered the Nokia E61 and haven't looked back once. My thoughts were captured here and here after I first received the device. I have been using the Nokia E61 now for two weeks now and am over the intial shock and awe I experience with a new device. However, I am still just as impressed with the device as I was from day 1 and so far it has performed flawlessly with everything I have thrown at it. The battery life has been excellent, connectivity is top notch, phone call quality is very good, the thumb keyboard is very easy to use and has helped me write emails, text messages, and short documents. I have had many people asking me questions about the device and a few have even made the decision to purchase one for themselves. If you are looking for a solid business phone, then I too can recommend the Nokia E61.