I wouldn't recommend cable in Japan for internet - get fiber optic or ADSL. Fiber optic is something like 100Mbps and ADSL, last time I checked, was at 40Mbps (and qwest tells me that 1.5 is "blazing fast"

). When you get there, you won't have a lot of trouble. NTT has an English page all about their internet services. Frankly, compared to the US, Japan broadband is CHEAP! Sometimes you can get cheap deals going through a different provider. I used Jens, but there were many others. Also, don't be conned by the myth that you MUST buy a phone line for $800. Nonsense. You can rent a line fairly cheaply directly from NTT. If you want to buy a line, lots of departing expats sell off fairly cheaply (¥10,000 is a good deal).
I think satellite for TV is the way to go if you are wanting some US comfort TV. Basically, everyone I know who had cable in Japan, canceled. They said the service was unreliable.
As for cellphones, deals there are better than the rip-off plans they have in the US. Docomo phones are cool, but they are also the most expensive...
Incidentally, Apple Japan has English support, so if you have a problem and haven't learned the language yet, you can call apple.
I don't know about apple care. My agreement says that it is only valid in the US. If I were you, I'd call apple first.
Finally, NO don't sell your mac just because you are moving to Japan. The mini is a good size, I suppose for most Japanese apartments. Laptops tend to be more popular because they are easily put away out of site...
do I sound like I miss it? I do...

Lucky you!
yt
edit: here are some links for you. I couldn't resist:
B-flets (fiber)
Flets (ADSL)
Jens