Ubuntu 9.04 Netbook Remix took about 36 seconds to boot to the Ubuntu login screen on an Acer Aspire One netbook with 512MB RAM and a 8GB SSD. This time I recorded the boot time of Windows 7 Beta booting to the login screen on an Asus Eee PC 1000HA netbook with 1GB RAM and a 160GB hard drive. It took about 35 seconds.
Of course, Windows gets really busy after the login process with anti-spyware, anti-virus, and bunches of different app update background processes. So, it takes about another 30+ seconds to settle down.