that's why fixed isn't the right word. instead, they want this feature to be added. it makes me wonder, though, if they just didn't have time to put that feature in or if it was a deliberate decision based off how much screen real estate would have been taken to put landscape text support in everything. but since they put it in the browser, why didn't they put it everywhere else?
Given all the attention put into the phone, I am sure it was deliberate. But.... take SMS messaging, the keyboard does not come up until you want to type giving you plenty of screen to read the history of the conversation. In landscape, you would also have room to review. However, once the keyboard is up you have VERY little room to again review of scroll although often one may not. If need be, once the scroll action happens the keyboards tucks away until you need to finish what you started typing. So its possible if not just a little less efficient.
In safari, once you bring up the URL field, odds are you will not be doing any scrolling. Yet, posting in this forum in landscape is a pain anyway in landscape - especially waiting for the rest of the page is loaded after you already click in the message pane - which brings up the keyboard. When that happens, the URL is still loading, keyboard is up and you have no room to scroll to the top of the reply box anyway....
I think once they get enough feedback, they will maybe make the landscape keyboard an option. Maybe one that can be set on or off on a per application basis. So at first yes, I think is was based on screen real-estate AND the applications need to be able to go into landscape - SMS does not need to be in landscape. However, many like the landscape keyboard and there is no reason SMS can NOT be in landscape....
So hopefully a feature will be added to allow this.