Update: Don't Mess With Taxes has a different revised schedule, with direct deposit rebates being completed on May 12.
Thanks to Living Almost Large for letting me know that I can expect to get my tax rebate early. According to this MSN article, direct deposit rebates will start going out on Monday (four days earlier than the original schedule). What's more, all direct deposit rebates are expected to be completed by next Friday, May 2 (the day they were supposed to start).
Tax rebates being sent by mail will start going out on May 9, a week earlier than originally scheduled. But the completion date for mailed rebates remains the same (July 11).