Is there any point in writing pre-Mango (7.0) Windows Phone 7 applications

Question

Inspired by an exchange on a recent question, I wanted to know whether there is any good reason to develop Windows Phone 7 applications that target pre-Mango models, i.e. by

Answer 1

I don't do 7.0-specific programming any more since the roll out of Mango is now available pretty much everywhere I'm interesting in deploying apps. This question will rear it's head again when vNext is released (with potentially updated hardware requirements / sensors, etc), but for now I can't see much reason to target the old version.