An excerpt from Steven Levy’s take
But when it comes to syncing with your computer, the Nexus isn't so great. This reflects Google's philosophy that if something ain't in the cloud, it probably ain't worth bothering about. Yes, you can plug a Nexus into your laptop via USB, but you have to trigger a command to mount it before the icon shows up, and then you have to drag the files over. Clearly Google would prefer that you use your Nexus One to hear music from Pandora or Last.FM and watch videos from TV.Com or YouTube, as opposed to the antiquated practice of copying and playing actual files.
That's also probably why Google sniffs at the idea of building in gigabytes of onboard memory on the Nexus. The phone comes with a miserable 512 MB of built-in flash memory. Google's message for those who want to store MP3 files, photos or movies? Let them buy SD cards! (There's a slot for that, preloaded with a 4-GB card.)
In other words, Google thinks a phone should be your connection to the cloud, which in turn hooks you to other humans, entertainment, the detritus of your professional life and, of course, any queries that can be answered by searching the vast Google indexes.