According to the Magic Box, yes! And worldwide too! Here’s some more information:
Sega announced that Phantasy Star Online for Dreamcast will be released worldwide this summer, the latest installment of the popular RPG series, this time up to 4 players can participate in one game over the internet. It is possible to search for players in the game server, using registered ID, there is also an automatic detect function that allows you to send out requests to specific players or friends on the game server to ask them to join the game. Because the game will be released worldwide, all the conversation in the game are done by using a set of graphical symbols and pre-defined phrases.