Or another, similar hemorrhagic fever.
I'm currently reading "The Hot Zone," and the author hints at the idea that the Black Death could have been an Ebola-like virus, instead of the bubonic plague as we traditionally understand. I was intrigued by this idea, so I looked into it, and it looks like there are some recent articles that support the idea. They mainly site evidence like the speed of the spread of the plague, and the lack of reports of a die-off in rat populations at the time of the Black Death.
Is this an idea that has much mainstream support or research to support it? Is there any idea as to how a tropical disease like Ebola could have found it's way to Europe at that time?
No, that's ridiculous.
Almost none of the archaeological evidence or written accounts support the idea that it wasn't mainly yersinia pestis, and very, very strongly supports the idea that it was. We've dug up Black Death victims and found yersinia pestis in abundance. Most notably, the main symptom of Bubonic Plague is the swelling of lymph nodes, which creates the buboes clustered around the groin and armpits (because that's where most of the lymph nodes are). This is well documented by contemporary writers all over Europe, but Ebola doesn't do that.
Bubonic Plague is what the popular imagination remembers it as, and Bubonic Plague indeed lacks the mortality rate or infection rate to wipe out half of Europe, but infections of yersinia pestis manifest in other ways, particularly as a respiratory illness called Pneumonic Plague. People at the time did not have enough medical knowledge to really understand what was happening, but they realised that the respiratory illness was the most deadly. This is what did most of the killing - Pneumonic Plague kills in about 36 hours, has a 95% mortality rate, and spreads through coughing. If one infected guy at the back of a crowded church started coughing, most of the town would have been dead in a week. Even then, the spread wasn't actually that rapid. It took 2-3 years to get through the British Isles, for example, which is quite a long time and too slow for many viral diseases.
I've written more detail about how the Black Death worked here.