After a week of hardcore usage on my iPhone first generation's new software,  I am ready to say that this upgrade is the turning point of the iPhone.  It is no longer a fancy, overpriced cell phone with iPod and Internet features. This device is the most capable mobile computing device available. With an interface even smoother than the Macintosh desktop operating system.  Although the operating systems behind both devices are the same, the ability to literally touch the information brings a whole new and more functional aspect to computing. With iPhone 2.0 software, the ability to use native applications is now available. These applications are extraordinarily useful.  For instance, the facebook app for the iPhone I have found to run much smoother and quicker, as well as more pleasing to the eye than its comparable web app. Although facebook (and others) have spent time optimizing their websites for the iPhone, the native apps are truly superior, and will continue to improve as updates are released.  On the flip side, with the new software update (2.0) I have noticed my iPhone being a bit buggier than it use to.  I have confidence that Apple will patch the holes, and in a timely manner as they did with iPhone 1.0.  Also, with many applications, as you open them, or attempt to use them, the iPhone may restart, or the app will return you to the home screen.  These issues are bugs in the apps made by third party vendors, and those vendors who are faithful in updating their work will soon work out the bugs.  This is new software, and a platform that no developers are completely familiar with yet.  The same problems occurred on both the Macintosh Desktop applications, and the Windows desktop applications.  Give it a few weeks and many of the applications with be patched and working to their full potential.