Now planning on buying some
Getting a touch-friendly, intuitive UI device, with decent, comprehensive and RELIABLE ActiveSync without clutter and various form-factors is pretty much impossible.
Used Nokia E series for a few years and whilst excellent technically the ActiveSync client sucks ass (require a reboot every week or so, password changes cause it to lock out the users AD account etc.) and the UI is bloody awful compared to an iPhone, Android or even a BlackBerry device.
BB is out as I don't want another middle layer in my messaging infrastructure at additional cost and overhead whilst providing nothing extra (Exchange 2010 does everything we require for our business natively). The iPhone is also no longer a contender due to the massive management overhead (iTunes will NEVER be installed on a device I manage - I shouldn't need it to 'activate' the handset) and limited control.
I'm then left with Android or WP7. Android has been my platform of choice personally for 2 years, and I'm still using a Desire. However fragmentation, UI considerations and above all the niggles i've had with ActiveSync (not as comprehensive as WP7, and not as slick either) as well as it's insistance on pushing Google everywhere (fine for consumers, however I don't want that for business use) has left me with little option.
I personally won't be looking at WP7 for a few months until I see copy & paste and a few more updates - however after playing with a HTC Mozart (low-end device really) I actually find it a very nice platform. Amazingly simple to use, however reasonably customisable, very intuitive and slick, responsive etc.
For business it ticks the boxes for me. My Exec Team will be getting them in the next couple of weeks (they can chose a Trophy or a Pro depending on a prefered form factor).
Once I can use the handset as a wifi point, couple of updates (just to ensure MS are keeping it current) and copy & paste I'll be moving from Android to WP7. Just seems like a nice compromise between the iPhone and Android.
P.S. Current Android user on a HTC Desire, rooted running MoDaCo custom ROM R9.