The Nexus S failed to have a micro SD slot as well. Major bummer. Regardless of how much space I use, I want the option to add more. Isn't that what Android is about, choices?
That's one of the killers of the Galaxy Nexus for me. Verizon just activated 4G in my area, and I am currently using a rooted/rom'd Thunderbolt, but I am going to either jump to the Bionic, Razr, or Nexus once they are all released.
What sucks about the Razr is the fact that the battery isn't user replaceable, so if battery life sucks, no shot at improving it. What sucks about the Bionic is that the bootloader is locked. What sucks about the Nexus is the lack of expandable storage. Which sucks less? Decisions, decisions.