I just tried to download the bzip archive using wget and instead of getting the actual archive i just got a file called "bzip" which is neither use nor ornament.
gzip and zip both download with wget, however both are missing their correct extensions and names.
I think it's because of the redirection thats been put in place on the new website. I.E., if you were to download it from a browser it would redirect you from the
http://mybboard.net/download/latest/gzip link to the actual file gzip (mybb_129.tar.gz)
It will be, the thing is that wget normally detects that kind of stuff, but for some reason it doesn't in this case.
To summarise:
If I download the zip file, I get a file called "latest" which I can uncompress to get the files.
If I download the gzip file, I get a file called "gzip" which I can uncompress and get the files.
If I download the bzip file, I get a file called "bzip" which is not an archive.