Land of the Dead was originally cut in theatres to achieve a US R rating. According to the reviews that I have read, the Region 1 version of this DVD is an uncut version that contains additional gore and approximately 4 minutes of extra footage. I haven't seen the movie theatrically so I can't say for sure, but my calculations indicate that the running time of the Region 4 version is exactly 4% shorter than the Region 1 version, which accounts for PAL speed-up. This suggests that the Region 4 release is also the uncut version.
Update 24Nov2005: I can now confirm that the Region 4 release is the uncut version.