I was at the HTC Titan launch party so got to play with Win7 phone for the first time a few months ago. I have to say it does deserve some credit for not falling into the iPhone style of user interface, but as an iPhone user for the past 4 years, I found it a struggle to come to terms with, my mind doesn't flow the way Win7Phone does and I found it awkward to use.
I think it wouldn't be such a problem though, if it was your first smart phone... But without a fully mature Ecosystem, why would someone choose the Win7phone platform?
