Japan leads the way ...
Here in Japan, there is no GSM, none whatsoever, and consequently there has never been any SMS or MMS before 3G (W-CDMA) services came along.
Instead, each operator has their own portfolio of different messaging services, some text only, some text and smileys (up to several thousand smileys, specifically designed for teenage girls), some text and photos. Of each type there are several different services providing larger capacity per message. Every such service is incompatible with any other such service and similar services are incompatible between operators. It's a huge mess.
As a result of this incompatibility mess, mobile phone based email was adopted much earlier on Japanese mobile phones than it was in the world of GSM and CDMA One. Each mobile phone user in Japan gets an email address from their mobile phone operator and the mobiles are automatically notified when a message has been received for them, so it has a similar instant delivery as SMS has. Other than the teenage girls who can easily spend 100 USD per month on sending smiley messages between them (if they are on the same network), everybody else in Japan has long become used to mobile email as the sole text and photo messaging service they would use even if their handsets still support all that legacy mess.
Now, with the launch of the iPhone 3G through Softbank (formerly Vodafone Japan), users simply get an email address associated with their iPhone to send each other text or photos, nobody will miss MMS, which is anyway only available on Softbank and Docomo 3G handsets, not on the other two operators which use different systems. On the iPhone, SMS is available, but none of the Japanese legacy messaging services are available. Apple did away with all that nonsense in a cleansweap, just like they did with abandoning floppies. This is a good thing because the very likely outcome will be that in 2 years from now, not a single Japanese mobile phone will support any of those legacy messaging services. SMS (and perhaps MMS) will still be there, but all the rest will likely be gone. None of the handset manufacturers which make handsets for the Japanese market has so far had the guts to get rid of this crap, Apple did. Everybody else will soon follow. It's always happening this way over here.
As the thousands of smileys messaging services will no longer be available, new generation of teenage girls will grow up with some other fad and the ones who are using this now will grow out of their teens and no longer miss the ability to send smiley messages. It's a fashion thing, like miniskirts, it will eventually fade away. MMS is just the same kind of thing. Get over it.
Besides, the iPhone is probably unique in that it has this App Store which makes it likely that MMS and other such outdated things may be supplied via some third party application. Why should Apple or Softbank waste their time to write such an app if somebody else can do it. MMS is obviously not on their list of priorities. They probably have done their homework to know what services are most important to their customers. And if they made a mistake estimating the importance of this or that missing feature, a third party app is likely to emerge, which is probably what they bank on. And if all else fails, no third party apps emerge and customers in significant numbers ask for it, then they can always invest some resources then and deliver the feature later on.
In any event, consolidation of the fragmented and cluttered messaging services into one unified standard (=> mobile email with instant notification) is something that makes sense and it is going to happen, just a matter of sooner or later. Apple are simply driving this change so it will happen sooner instead of later.
Sure, in Europe where there are only two different messaging services and all operators use those two and users can send messages between operators, the situation is not as ridiculous as it is/was here in Japan with so many different and incompatible messaging services that nobody really knows how many there are and what the differences are between them. But still, consolidation into a single service based on email makes sense nevertheless. Sure, some people will complain during a transitional period, but in a year or two, it will most likely be all but forgotten and those who scream about MMS now won't remember what all the fuzz was about.