I think I have the same question, but when you say home saring are you talking about on an Apple TV? My wife and I have an imac with seperate profiles, each profile has an itunes account, and we want to be able to both be able to access our itunes from the apple tv. We went under itunes and > advanced > and clicked on turn on home sharing for both accounts, we see each others libraby when logged onto other profile, but can't get the option on the Apple TV. We also went into I-tunes preferences and turned on sharing. I also beleive under the advanced option menu there is a place to share photos, (from i-photo). Hope this helps.
If I can just add a little weight to this subject. I have the same situation as the two users above. My partner has a computer with an Apple ID and I have my computer with my Apple ID. I thought it would be a simple matter on the AppleTV to just add another account, but alas that isn't possible apparently.
You would think that Apple would understand that many households, especially with families would have separate ID's!