Let the hive mind of Engadget get that for you.
"I just switched to Sprint from Verizon about three months ago for the Pre. Then I went for the Hero about a week ago. Now, I miss my hardware keyboard and am thinking about switching to the Moment. I am still able to switch back to Verizon if I want and get the Droid when it arrives. Should I just trade up to the Moment when it comes out, see if I like it, and if not switch to the Droid? Or something else entirely? Help!"
I checked it out and one packet is 128bytes.
My calculation after looking aorund and converting 128x20,750 was about 2.5Mb!?
So if you only use 2.5Mb or less you get the reduced rate (¥1,695), more than that the rate increases until you reach about 75,000 packets - that works out at 8.5Mb.
After that your on unlimited data that costs the original ¥5,985 per month.
So despite looking good value I don't think anyone will be paying less that the original ¥5,985 unlimited data.
Is it even possible for the iPhone to consume less than 8.5Mb per month?
Also, if I made a mistake with these numbers (they look suspect but I have researches several times and get the same outcome) please please let me know.
I agree that from a marketing point of view it may get more people to adopt the iPhone in Japan, but I think realistically all users will end up paying the same unlimited data rate ¥5,985 as before.