I just tested mine a few times. Each time took more than 2 minutes to get to a state where there was no obvious bootup lag. I don't have a secondary SD card, and only have about 100 songs on the internal SD, and a handful of videos and small photos. I don't think the media scanner is totally the issue (although I've noticed the media scanner runs twice, despite not having a second SD.)
Normally it's not a big deal, except on those rare occasions where it decides it can't send text messages and I need to reboot to have it start behaving correctly.
The only thing non-stock that I'm running at bootup is Startup Cleaner Pro, and using that to block the startup of several system apps (Hotspots, Daily Briefing, Google Talk, Instant Messaging, Maps.)
Even from day one, it was a slow boot. No idea why. Overall, though, I'll live with a slow bootup to have the other cool features.