Two other issues to think about are these:
1. Since the Nexus One is not running a home shell and core app replacement like the Incredible's Sense, it is far more likely that Google will have OS upgrades available for it before Verizon and HTC do for the Incredible, if the experience with the Hero and Eris are any indication.
2. Because the Nexus One is sold by Google and its hardware is supported by HTC, you will have multiple customer service support contacts to think about if you do have issues, and you have no store that you can go to for any repair or replacement. The Incredible will have a single point of contact for warranty, tech support, etc., and if you have a hardware failure you should be able to get the handset replaced at a Verizon Wireless Store.