Slashdotters have usually put Windows Phone 7 down because of the old clumsy feel of older Windows Mobile phones and the OS, but you have to remember WP7 is completely different beast and it's completely redesigned. Personally I think it has great future in front of it. They have the best phone manufacturer Nokia on board and WP7 is a huge advancement as OS. C# and other available languages along with Xbox Live and XNA integration is awesome or developers. For users the interface is at the same time innovative and easy to use, and they don't need to take a specific phone but can choose from wide array of phones the one that best suits them. Still WP7 doesn't have the fragmentation issue that Android has because Microsoft at least has some hardware requirements for the phones.
As soon as Nokia's Windows Phone 7 devices are released, I will probably get one. Both iPhone and Android have many issues caused mostly because they're fundamentally so far from each, like left and right. Microsoft's Windows Phone 7 is in the middle ground and takes the best from both worlds.