HTC HD 2 is a fine phone, nevertheless the main concern in my standpoint is the Windows OS it uses, see Windows Marketplace for Mobile (better known as Microsoft's app store) is fairly new, and i.e. has limited number of developers developing the apps; unlike iOS, RIM and Android platforms. Obviously it will take them some time to evolve, but the other competitors won't wait for MS, they'll up their game with every chance they would get.
Another point of concern with HD2 is that it uses Windows 6.5 in contrast to Microsoft's latest Win 7 mobile OS, the latter is better in so many ways but both HTC and MS refuse to update HD2's 6.5 OS to it. I'm not certain which one is to blame more...
Just to give you some figures, as of today there only 3000 apps in Windows Phone 7 Marketplace, and that doesn't include Windows Marketplace for Mobile (this is a pre-Windows 7 mobile OS app store), RIM has 14,500 apps, Nokia's Ovi Store has 28,000 apps, and Apple's App store has 300,000 apps according to a study conducted in November, 2010.
What I'm trying to express is this, the magic all lies in the software, since once you've bought a phone you can't change it's hardware namely processor, RAM and other innards, however with apps you can do countless things on it, and with smartphones almost giving computers a run for their money; my suggestion is to buy a phone that has established app store, unless of course you aren't so savvy and like to use your cellphone just as a traditional phone, and won't be taking advantage of the extra features it could offer in conjunction with apps.
