They look like hidden wedges, and YES they are extremely trendy right now. If you like them then get them. I think they look extremely sexy.. The hidden heel will give your legs more definition especially in the calf.
However, If you don't like them than dont. It's as simple as that. Wear whatever you feel comfortable in and whatever is you. Like you said, they are a trend and will eventually die out so if your not really feeling them than just go with something else that you can wear a little bit longer and still remain fashionable!