My Galaxy Nexus 4.0.2 takes over three minutes to boot. Is this normal? Is it supposed to take this long to boot? Why does it take so long?
My Galaxy Nexus (I9250, GSM version) with Android 4.02 definitely doesn't take that long to boot.
Just switched mine off to test, and from off it takes just under a minute to get to the SIM card PIN unlock code screen (and after entering my PIN it goes straight to the pattern lock with my normal wallpaper).
You may have encrypted your phone contents. Both of my phones take a lot longer to boot since having to decrypt on start-up.