Building against the 10.7 SDK will not succeed, as the MacOSX code at least in vcl uses some APIs that have been removed completely in the 10.7 SDK. (They were deprecated already in 10.4... which shows the state the Mac code is in.)
So either some Mac expert need to really do some hard work on the Mac code (presumably duplicating much of the NeoOffice work...), or the 10.6 SDK is the most current one you can use. I know because I have just been trying. (Well, trying to build LO against it, but the Mac-specific code shouldn't be different in LO and AOOo as far as I know.) (There will be minor glitches here and there when building against the 10.6 SDK; they should be relatively easy to fix.) --tml
