Windows Vista RC1 was just posted on Microsoft Connect. (~2:45 EST)
x86
vista_5600.16384.060829-2230_x86fre_client-LR1CFRE_EN_DVD.iso
x64
vista_5600.16384.060829-2230_x64fre_client-LR1CxFRE_EN_DVD.iso
Screenshots and impressions of RC1 will be posted shortly once a few staff members get the build downloaded and installed.
Update: Jim Allchin has released his RC1 statement. Click Here for the whole letter.