I think you'll be losing a lot of potential users by the splash page and login procedure. I suggest removing the splash page all together and perhaps give a preview which encourages visitors to sign up. At the moment the visitors doesn't know what to expect and most people won't give their email address untill they do.
Also, since you're chat channels are bit inactive at the moment, give the user some other content while he waits for other chatters. I suggest aggregating a RSS feed if possible.