For those of you planning on getting the Broadband Adapter just for Phantasy Star Online ... be careful. The Japan version doesn't support the adapter, and although Sega US is claiming the domestic version will, there have been many conflicting answers.
It's RARE for a game to have features added on conversion, and especially ones that can introduce HUGE bugs like changing the online system to support an upgraded peripheral. It's a huge risk, and I wouldn't count on Sega doing it.
Plus, Sega US is usually clueless when it comes to games being posted for US release. It wouldn't be the first time they claimed a game would have x-feature and didn't on release.
I'm not saying it won't happen, just saying to take the news with a grain of salt.
That said, get the broadband adapter anyway. If you've got high-speed access, there isn't any good reason not to have it. It's not like you can't flip back to modem if you need to.