It's not as much a question of not having email as it is the ease-of-use for people to snap a picture with their phone and text it to someone. A lot of my friends do that and IO'm constantly getting those viewmymessage.com texts. Its like any systems-change, it takes time to get people to start sending texts to your email instead of your phone #.
SMS, MMS and WAP are all GSM technology relics. 3G and push e-mail on every phone is the way to go. Emails have no limits like 160chars - single SMS, MMS's content and image size limits and so on.
I don't know why this question about mms always turns into a debate of do we need or not. Every feature of the iPhone could be debated as needed or not. I don't know why we can't just either answer the question or leave the post alone.
If you want to debate this subject then start your own thread!!!
This is a stupid debate to be having. MMS has been around for years and you can now get that feature on a phone where the company actually pays you to take the crap phone off their hands. Apple should without a doubt add this feature to the 3G iPhone.