Quick update on why there is no final 0.5 release out yet:
Short answer: because I'm really paranoid about bitcoin binary builds, and the switch to Qt means a change in the way the builds are done.
Linux builds should be all set; the 'gitian' trusted build process works nicely.
Windows builds are being difficult; we need a gcc expert to help debug the 'gitian' cross-compile (see https://github.com/bitcoin/bitcoin/pull/587
Unless somebody steps forward and says "I'll support compiling bitcoin-qt/bitcoind with Visual Studio) I'm going to remove src/makefile.vc and make sure the readmes say that only the mingw toolchain is supported.
Mac builds were slightly broken for the 0.4 release (they don't run on OSX 10.5-- you need 10.6 or greater). I'm "recompiling the world" to hopefully fix that, and hope to have mac binaries available soon (let me know if you can help test, especially if you have a 32-bit Intel mac running 10.5).
On my wish list for builds (anybody want to volunteer?):
I think it'd be spiffy to have a .pro file to compile bitcoind; maintaining N different makefiles is annoying and error-prone.