The official Street Fighter IV blog has updated today and this time around, they have answered a bunch of questions that the users have asked over the past couple of weeks. You can find the
original blog entry here but since it's all in Japanese, here is a summary of the most important points from the blog. Please note that they often talk about a "title update" in many of the answers, and I can only assume they're talking about the free DLC that will add the championship and replay modes to the game.
※When the game gets updated, there will be changes to the base game and characters. What changes will be made is unknown, but the "obvious points" will be addressed. You know as much as I do on this.
※Neither Dee Jay nor T.Hawk will make an appearance after the title update.
※No decision on new costumes for the home version, but during the summer there will be some sort of special announcement. No hint on what it will be though.
※Cannot comment on whether Shin Akuma or Evil Ryu will make an appearance in future updates. Sticking closer to the source language, they state that they haven't decided on this.
※After the title update, there will be a disconnect rate/ratio shown with every player. However, since there is always the situation that a connection may be very laggy and disconnect by accident, over time the disconnect ratio will decrease. The wording on this is kind of strange, because if you think about it, sure, if you have a high disconnect rate and then don't disconnect for a long period of time, of course the ratio will go down, but perhaps there is some sort of extra penalty associated with disconnecting.
※No plans for a Mac version of SF4.
※Will announce the release date of the PC version very soon. As a bonus for PC gamers who have waited for so long, they'll receive a nice surprise with their version of the game.
※Cannot comment on the arcade version receiving an update to include the console exclusive characters, but they would like to add them if they can.
