My initial impressions are

• This is the best looking Android phone yet. I can easily imagine trading my iPhone 3G for Nexus One, if I wasn’t under contract.
• I really like that they are emphasizing consumer choice. You can get it unlocked today and bring it to any carrier that can support the hardware. Later, they’ll give you multiple options for contacts with providers. Today they feature T-Mobile and plan to have Verizon soon.
• One of the criticisms of previous Android phones had been a lack of responsiveness, presumably due to hardware limitations. They boosted the chip speed considerably for this phone and it sounds like it is now very responsive.
• I expect that when Apple announced the next iPhone, it will blow this phone out of the water. Part of me is rooting for that because I really like technology is advance, but part of me is rooting against a strong iPhone response because I would like Android to pull ahead of the iPhone.

Android apps are still playing catch-up to the iPhone app store, but I can only imagine that it will catch-up in most respects. Developer freedom, like any kind of freedom, is a powerful fertilizer. Amazing things grow in it.