Confirmed running Windows 8 64-bit.
It also appears that the launcher keeps you logged in, but yet the option is not available to turn on or off.
Development Console:
Launcher 1.0 (through bootstrap 4) started on windows...
System.getProperty('os.name') == 'Windows 8'
System.getProperty('os.version') == '6.2'
System.getProperty('os.arch') == 'amd64'
System.getProperty('java.version') == '1.7.0_21'
System.getProperty('java.vendor') == 'Oracle Corporation'
Loaded 1 profile(s); selected '(Default)'
Delta time to compare resources: 568 ms
Download job 'Resources' skipped as there are no files to download
Job 'Resources' finished successfully
Logging in with the old launcher with "Keep me logged in" fixes this issue.