The new wallet is finally in beta. Builds for Windows (32 bit NT and above) and Mac (OS X 10.7 and above) are available. Links are below.
Several screens are still under construction, the buttons for which will not work.
An automated installer and draggable disk image will be available soon for Windows and Mac, respectively. The screens under construction will be finished soon. Signed executables will also be available soon. The block explorer will also be fixed.
Windows Manual Installation
OS X Manual Installation
How to use the bootstrap.dat