I don't think there's a partnership between GSL and MLG this year. Instead, they changed it so that they are awarding seeds based on all international results instead of just MLGs.
Kind of related, Slasher was up in arms on Twitter about IPL4 being on the same weekend as PAX East. I kind of hope that's a precursor to some SC2 stuff going on at PAX, because I'm going. Probably not though