According to a press release from the Illinois Supreme Court today, "The Illinois Supreme Court Clerk's Office will join the eFileIL e-filing community on Thursday, June 15. Filers for the state's highest court will need to access the eFileIL filing platform at efile.illinoiscourts.gov and become a registered user through one of the authorized service providers. Supreme Court filers will no longer be able to use the i2File platform as of 11:59 p.m. on Wednesday, June 14."
The full press release can be viewed here.