Some of you may have the impression that 8.2 already builds with Visual C++. And it does. Just not quite all of it, and with a lot of rough edges. Hopefully, 8.3 will be much nicer in that regard. The current goal is to get it up on the buildfarm as soon as possible to make it a "proper platform". Unfortunately, I don't know the buildfarm code well enough to do that part myself without a lot of learning to do first.
It's not that far off. There's still one fairly large patch to the regression tests themselves to make it work (or rather, to the regression test execution program), but the really big parts of it are in. Then it needs some glue to make it run nicer. Having to remember a three lines long command line is not very nice...
There have been plenty of small fixes to make it work in environments that aren't identical to mine, and I know there is at least one more pending. And I just submitted a patch to clean up most of the compiler warnings created (because VC++ sees other warnings than gcc and friends).
Bottom line - it's now definitely supposed to be in a state where others can try it out. So if you are interested and have the time, more testers are definitly needed. You need VC++ 2005 (Express should work fine) and current CVS-HEAD of PostgreSQL. All the vc stuff is in src/tools/msvc, see the README file.