Also, later on (if you leave them on for now) and the stickers fade, when you do finally peel them off there may be a slight difference in the paint that was protected from UV all that time where it's going to look slightly brighter from the lack of fading/oxidation over the years.
I always peel them off, except as I stated in another thread about this awhile back on my 4 wheeler. I took some off, but replaced others with various other "warning" decals from other things that looked like they belong. My favorite was a warning sticker I removed about riding two up or something and replaced it with one from the kids trampoline that said "do not attempt backflips". You didn't notice it at all unless you happened to actually read it!
If you keep a maintenance log or something as part of your manual binder and you want to keep them...have at it, but get them off the bike!