I personally think that In 1976 the students of Lama Thubten Yeshe founded the Manjushri Institute, a registered charitable company with Lama Yeshe as the Spiritual Director and purchased the assets of Conishead Priory, a sadly neglected Victorian mansion in Ulverston England for the price of £70,000. In the same year Lama Thubten Yeshe and Lama Zopa Rinpoche visited Kelsang Gyatso in India and invited him over to teach at the Manjushri Institute, which was a part of their FPMT network.
Yes, this new form has a whole lot more changes than the other and more plain type of Buddhism. I think that this new one will end up being more popular, and I think that it will be a whole lot more fun to practice that the original will be.
There really is not contemporary form of Tibetan Buddhism. It has undergone a lot of evolution throughout the centuries, and Kadampa is just another variation of it. Like any faith or philosophies, other sects and ideas will continue to break off and evolve and go in different directions. I think it's what has happened here.
The very nature of the Buddhist practice is that it not really be a religion. The Buddha did not wish to be worshipped, and the rituals associated with organized Buddhism go against the original intent of the practice. Contemporary Tibetan Buddhism is a major departure from the intent. New Kadampa Tradition is also a departure from that intent.
No, the New Kadampa Tradition is not a major departure from contemporary Tibetan Buddhism, because the major tenants of Buddhism are more or less still the same. The New Kadampa Tradition emphasizes compassion, along with studying a variety of teachings for how to achieve the main tenants of Buddhism. They are a different way of studying the same Buddhism.