Funny that you should mention addresses and the mistakes users can make in writing them:
In my younger days, I had a penpal in eastern Europe. My first letter to her took three months to get to her, not because the postal system was so bad, but because I misread her handwriting and what I thought was “Gyll” was actually the number “6411”…it was the human touch that finally ensured that she got my letter. After that she usually typed her return address on to the envelope 
I once tried setting up an application to first ask for the zip code (using an autocomplete combobox) because that immediately gives you the state and narrows the possible choices of city, leaving the street address to be typed in. It was too different for the user even though it was simpler and more accurate. The user felt the data entry was ‘backward’ because the zip code was always last in their memory of an address.
I agree that UI experimentation is a good thing, and I think that you are doing a service to your readers by question convention.
I think it’s interesting to look at conventions in terms of their network effect, with similarities to media formats. One website that had a free text address entry field would be an oddity, and there is not doubt in my mind that it would confuse a certain, if small, percentage of the site’s users. If it’s a good convention, more people adopt the convention, which leads to more user familiarity, and so on. If, on the other hand, few people adopt the convention, you’re going to continue to confuse a percentage of your users.
Your UI innovation examples - Tivo, Media Center, Office 12 - were all solutions to very real problems. Television sized display and remote controls require a new interface. Office 12’s ribbon system is a response to feature overload.
What real problem does changing the way we enter address solve? It’s a small amount of mindless work, which we’re replacing with pretty much the same amount of work, only it’s no longer mindless.
Rimantas-
True, webforms vary, but there are well established conventions with few variations on basic user information items - first name, last name, address 1, address 2, city, state / region, postal code, country, email, confirm email, phone area code, phone prefix, phone suffix, phone extension. (Can you tell I’ve been working on some registration systems lately?)