The Queensland State Archives has progressively added indexes available on-line for records in their keeping. These indexes can be found at: www.archives.qld.gov.au/research/indexes.asp
Most recently they have added to the index of Probate records and currently there are indexes for All Districts 1857-1900 and the Southern District from 1900-30. Northern and Central Districts have yet to be indexed beyond 1900. 1857 is the date of the creation of the State of Queensland, Australia. Prior to that the norther-eastern part of Australia, was administratively part of New South Wales, where any relevant records would be found.
The specific link to Probate Records is at: www.archives.qld.gov.au/research/index/wills.asp