I don't think so and I'll tell you why. Even though it's been around for quite some time I don't see any sign of it waning. After a couple decades I thought surely folks would tire of witches, vampires and shape shifters but not only do I continue to see it on bookshelves but flip through the television channels and you'll see "Once Upon A Time," "True Blood" and "Grim" among many others.
Either we all have a wild imagination or people are a messed up bunch these days. I tend to believe it's a little bit of both.
You also don't have to stick to the rules. Dracula couldn't look at a crucifix, see his reflection or be seen in daylight but look at all the new vampires and you'll see all sorts of changes. Some quite silly but none the less you can have your creatures do just about anything you want these days.
When writing we must keep up with what is popular but don't let that limit your imagination. If you want to write something no one else is attempting by all means go for it. You just might come up with the next break out genre or have a story that overshadows anything else that is out there.
Those of you writing about dragons and demons wondering if by the time your story is finished there will still be an interest, have no fear. The snowball that J.K.Rowling let loose in the 90's has gained momentum and doesn't appear to be crashing yet.
I truly believe there will always be people who enjoy reading fairy tales and as long as you write a good one someone will read it. Writing well is the key. Just because you put a vampire or fallen angel in your story doesn't mean people will buy it and if they do buy it and it's bad, they'll certainly let you and everyone else know about it. Read Amazon reviews when you have some spare time and you'll see just how verbal people can be about what they like and detest.
I read a blog a while back by a writer who was taking a break from fantasy stating that she felt readers were tired of that genre. No, I think the writer exhausted her ideas and her readers could tell.
The problem with writing the same genre all the time is eventually all writers run out of steam. When you see them adding really weird stuff that's a clue they've come to the end of that road. It doesn't mean her audience no longer wants to read that genre it means she needs to take a break and try her hand at something else for a while. Don't stop writing just write something else.
Agents and editors make a mistake when they tell an author to only write more of what has already sold. Some authors use a different pseudonym so they can work on other things because they get burned out. Yes, writing more of what already sold sells books but eventually all wells go dry.
If you love paranormal and enjoy writing it then keep going. If at some point you feel you've exhausted your ideas, move on. There are dozens of genres out there and new ones being created all the time.
I read an article recently that a new growing niche of books are for college age kids. I thought most books were for the 20 year old age group but apparently not and agents are looking for books written for those just out of high school and finding themselves. I forgot the name of the genre but it has it's own title now. So if YA isn't cutting it for you perhaps you might move up a few years and try your hand at writing for college students.