The official ILM website posted a document on Mark Miller's promotion to VP and Senior Executive in Charge of Production (noted here several weeks ago). But it also seems to confirm that ILM will indeed work on The Mask sequel (tentatively titled Son of the Mask), which was previously hinted by Tom Bertino at SIGGRAPH 2003.
The Mask sequel is slated to start filming in Australia around November 24, 2003 and to eventually wrap shooting in Los Angeles. Jamie Kennedy will play an aspiring cartoonist whose newborn kid inherits the powers of the mask of Loki (played by Alan Cumming). No original cast members are set to return. The film will be directed by Larry Guterman, who previously did Cats & Dogs, from a script by newcomer Lance Khazei. No VFX Supervisor is known at the moment but it would be a good bet to say that Animation Director Tom Bertino might be involved. The movie is slated to open October 8, 2004. You can read the press release here: