I wouldn't worry too much, its just a breather. I would take some dressing though (armor all or similar) and moisten the rubber hoses on your engine though to slow the speed of decay. Looks like you could do well with a nice engine cleaning too, just do a search, it takes 10-45 minutes depending on how detailed you want to get. If the hose decays more though, it might cause a leak and create a vacuum (the other end is attached to the manifold I believe) and that will throw your A/F mixture off and it won't idle right. It wouldn't cost much to replace.