If the iPhone can survive not having MMS in the first year with THEIR target audience, it should matter even less for N900 and their more tech-savvy audience.

The first iPhone didn't even have 3G for crying out loud.

I'm sure you can find much better IP based data transfer system with all the mashup of tech available nowadays and make use of the WiFi and 3G to accomplish the task.

PS: Is there email-to-MMS service somewhere, maybe?