Unless you run across any unusal noise that would be a detraction from the party, this ought to work real well! Specifically, some CD players (this probably doesn't apply to the iPod) have a small "beep" when turned on and off / forward-reverse. This is HIGHLY amplified when running the CD player in to an amp. Trust me, you'll only want to hear it once! As well, be sure to run the proper output and adaptor (stereo out from the iPod with a stereo-to-mono adaptor before going into the amp). In some cases, you may lose one of the two stereo channels if not adapted correctly. In this case, you'll notice some of the song missing (I lose Eddie's lead channel on Van Halen tunes). I found a nice setup at Radio Shack. I use a 6' male to male 1/8" stereo cable out of the laptop (or iPod in your case) and a 1/8" stereo female-to-1/4" mono male adaptor (yep, Radio Shack carries one of these little lifesavers!) going into the amp.
I've run CD players and my laptop into a variety of amps (guitar, bass and PA) with great results. I recently moved to a Behringer KX1200 as a small/medium club gig amp so that I could cut down on my gear and have (4) independent input channels. For a recent small outdoor party, I ran my laptop (MP3's) into two channels (1/8" stereo out of the laptop to (2) mono 1/4" inputs) of the KX1200. Set the EQ flat and had some of the best sound (both volume and tone) that I've ever had out of a combo. It was WAY beyond what I thought it could do!
I've used my bass amps coupled with a CD player on several occasions to play intermission music during gigs (the PA will often do a better job, but you may find that you don't have enough PA inputs or going through your bass amp is easier).
In the end, PA, home stereo, guitar, keyboard and bass amps are similar animals. The biggest difference is how they are "voiced" electronically. Essentially you would need to EQ each differently to get similar sounds. Otherwise, most will work well for broadcast applications.
