While I certainly wouldn't mind any improvements Apple might make to PhotoStream, I guess I just don't see the problem. PhotoStream is only viewable on my own devices so ... who cares if a bad shot is in there? It won't be there permanently, it "falls off" after 30 days. I love having instant easy access to a stream of photos that automatically migrates to my iPhoto and iPad wirelessly -- incredibly convenient compared to the way we used to get them on there, plus I don't have to worry about syncing photos to the iPhone anymore.
Last time I went on a trip I loaned my wife my iPhone 4 since I couldn't use it where I was going. I took the iPad instead. She didn't know about PhotoStream and as a result, I finally discovered what she does with herself while I'm away -- she goes to the shops and tries on coats and shoes and takes photos of them!
We were using FaceTime and I told her I didn't like that coat she tried on and she was SHOCKED, she thought she must have accidentally posted to Facebook or something. I told her about PhotoStream and we had a good laugh about it, but now she's more careful when she's borrowing my iPhone!
I have PhotoStream set up so that any photos I take with the iPhone automatically go into it (and thus get transferred to my Mac and iPad), but any photos I add to iPhoto *don't* automatically go in unless I drag them into the PhotoStream folder. This works great for me.