I was abused as a child so I feel obliged to comment here. I know what I want to say, but I'm not sure I'm articulate enough to express it.
My issue isn't with the principle expressed in the OP - I think few people would call for jailtime on the basis of pure 'thought-crime'.
My issue is with the definition of 'paedophile' as a sexual orientation. First of all, I think that the acceptance of homosexuality has encouraged a sort of binary view of sexuality: you're either born straight or gay, and that's genetic. It stands to reason, the argument seems to go, that other sexual orientations could also exist, defined by attraction to other groups. However, sexuality is much more fluid than that; few people are solely hetero- or homosexual, and everyone has their own preferences and sexual idiosyncrasies. I remember a story in the papers a while back about some guy who was caught having sex with a bike (somehow), but it would be odd to classify him as 'cyclosexual' or some such just because he got the horn and went for it with a BMX. A person's sexual interests can change over their lifetime, and dependent on context.
The context in which most children are abused is in the context of their vulnerability and the adult's opportunity. I don't believe that abusers are attracted to children, as such; rather, they see an opportunity for sexual gratification and take advantage of it. Children are easy targets, especially vulnerable ones. If abusers are attracted to anything other than the opportunity itself, it's the nature of that vulnerability and the power they can exert over another person. In my experience it is very much entwined with misogyny (I would argue that this is the case even in the abuse of male children, who are weak and vulnerable and therefore, in a sense, feminine). Abusers are not primarily enjoying the object (in this case, the child) of their abuses: they're enjoying the abuse itself.
I'm heterosexual, but I feel quite confident that, were sex with adult males outlawed tomorrow, I'd be able to control myself and wouldn't feel the need to force myself on vulnerable men - even more so if that were harmful to them, made them scared or caused them pain. There would be no danger of me overstepping that boundary because the thought of hurting another person is abhorrent to me.
Rapists do not have an 'orientation' that causes them to be tragically attracted to terrified men and women. Rather, they actively seek out opportunities to hurt others. They enjoy hurting others. Their sexual 'preference' is an extension of their own egotism, sadism and sense of entitlement to the bodies of other people. Child abusers are the same. They are not attracted to children; they are attracted to sexual gratification, and they're either indifferent to or turned on by the suffering they cause.
I hope I expressed myself clearly. I don't see that it can be an 'orientation' when the very essence of it is domination, subjugation and sadism exerted over the genuinely vulnerable (unlike BDSM between consenting adults); those are the contextual factors that would MAKE children attractive. The concept of childhood itself is surely too bound up in ideas about vulnerability, trust and 'innocence' to be divorced from those in the mind of even the most theoretical, tragic, non-criminal 'paedophile'.
Having said that, I do hope that people who may have these feelings are able to access treatment - I just don't think they'll want to for the reasons I've given above.