You can still log in using this method:

Press start->run
Type: secpol.msc
Press enter
Expand local policies
Click Security Options
Double-click "Interactive Login: Do not display last user name"
Check Enabled
Click OK
With both of these settings in place, the same functionality of the old-style "Press CTRL + ALT + DEL to login" window is achieved.

Vista How to disable welcome screen and fast user switching?