I used to do a lot of car stereo installs all the way through college. That blue wire is for a power antenna, which would be pretty cool on a bike, but you're looking at a little more work and money. Still, it'd be pretty cool. There's also usually an orange wire (I believe orange) to hook up as a remote to any amps that you add down the road.
I know stereo's, but I'm not too fresh on the alarms. What I do know about the alarm, is that it's always hot. If you want to hook up to the alarm, you should just ask your dealer which is the power lead to the alarm. I'm not sure what color that wire is. I have an alarm on my bike too, but I haven't dug into it.