@dentaku: It is unfortunate but I understand the reasoning. The high end models are going for a high end feel (like the iPhone) so the are going for solid back plates. Covers for ports tend to give a less solid feel.. The lower end models are going for being inexpensive so putting in a micro SD slot must be cheaper than putting in the actual memory. That way the users that want it can spend extra money to put in more memory.
I really would like the option to add memory, but as long as they have 32 GB I can live without it.