When running phpunit.bat on a freshly installed 3.5.0RC1 I get an error like "Files not expected" (sorry if it's not the real error, my OS is not english). A bit of debugging showed that the path environment variable PHPBIN was had double "double quotes". I'm not a .bat expert but here's one that works for me:

if "%PHPBIN%" == "" set PHPBIN=C:\Program Files (x86)\PHP\php.exe
if not exist "%PHPBIN%" if "%PHP_PEAR_PHP_BIN%" neq "" goto USE_PEAR_PATH
GOTO RUN
:USE_PEAR_PATH
set PHPBIN=%PHP_PEAR_PHP_BIN%
:RUN
"%PHPBIN%" "C:\Program Files (x86)\php\phpunit" %*