Absolutley I would, yes, there are are few niggles but this is version 1 of the software and a brand new device FFS. Apple are STILL having problems withe the iphone 4 even now (alarms cannot deal with move to GMT from BST for example). With WP7 you are buying into one of the most promising new mobile phone OS's of recent times IMHO, with the HD7 in particular, you are getting a cool big screen device from a company that has built up a good name for itself in the industry. I currently own the HTC Desire and the HTC HD7. I will be keeping the Desire only until the Kindle app and HTML5/ Flash land for WP7, then that will go on Ebay.
My only fear is that because MS decided to launch without one or two features (Flash/ CutnPaste and turn by turn Nav) it will get hammered by the critics in the tech press and be stillborn. This would be a tragedy - the more competition there is in the smartphone space the better for the consumer.
I also hope the handset manufacturers give it the attention it deserves, recent reports on build quality issues with the HTC Trophy do not bode well
Past: i-mate jam, XDA Exec, XDA Orbit, XDA Stellar, Palm Treo Pro,HTC Diamond
HTC Diamond 2 (with Dutty 6.5, Sense Ultimate R6), Palm Pre, HTC HD2, HTC Desire, HTC HD7: NOW HTC TITAN X310e and Motorola XOOM and HTC one x