Only peaceful resolution, and therefore the only solution, is self-determination; that too under international eyes. This is something that was promised, and should have happened, back in 1948. It didn't happen then, but better late than never. Let all the people who currently reside in AJK and IHK vote, but freeze immigration in and out of the region; that is the only way to ensure a certain overly-populated country can't pump the region with its own people and dilute the elections.
There will be regions in the South and South West that will vote for India, I have few doubts. But I also have little doubt that the majority of the area will vote to separate from India and become part of Pakistan. Once the Kashmiris have let their voices be heard, the border can be made permanent between the areas that voted for either side, and both India and Pakistan can move towards building a controlled yet soft border (much like US-Canada). This will ensure that future generations can freely visit each others' countries and promote brotherhood in the region. In the long run, allowing the Kashmiris to decide their own fate will benefit both countries, and I don't understand why my Indian friends don't realize that!
As for the solution presented. The Line of Control divides the people of Kashmir, particularly the valley. We, neither Indians nor Pakistans, have the right to divide a people without their consent. They've suffered because of us for many decades, and are becoming increasingly frustrated with both countries (yes, Pakistan as well, but to a far lesser extent).
If the issue is not resolved, who knows how many more will die in this century. If Kashmir is resolved, then every other issue standing in the way of peace; Indus Water and whatnot, can be very easily resolved as well. I swear, the people of Pakistan will shower you with flowers if you just opened your damned eyes!
Edit
Well, one key issue I forgot to mention. Whereas Pakistan has primarily the Kashmir issue to worry about, India has many others. The problem is, if a plebiscite is held in Kashmir, it may fuel uprisings elsewhere. Assam, for example, would be difficult to keep under control.
Things are complicated for India. I can understand why it is a touchy subject, and I sympathize with them. No patriot wants their country to be divided. However, the facts remain the facts. If you're an Indian reading this and are against Kashmiri self-determination, then I implore you to visit the Valley and speak with the locals. I've done the same on this side of the border.