From their Inside Adwords blog
Enhanced campaigns help you reach people with the right ads based on their context – including location, time of day and device – without having to set up and manage several separate campaigns. For most advertisers, upgrading is a simple 3-step process. Already, advertisers have upgraded more than 1.5 million campaigns and seen strong results.
While many Adwords users might disagree it is the way of the future. Here is the Inside Adwords explanation of the new upgrade center followed by a screenshot which is a bit hard to see but you get the idea.