We've heard from various sources that Nintendo is planning on developing a "Switch Pro" of sorts for several years.
From the jump, outlets have reported that Nintendo has been looking into upgrading the Switch's hardware to be more competitive; but outside of nebulous release windows (that have all came and went), there aren't very many specifics. Now we have more hope thanks to a report from Bloomberg.
As Bloomberg states, Nintendo "has looked into including more computing power and 4K high-definition graphics," which would come in the form of a new Switch. That Switch could come next year, and an analyst predicts that with that additional hardware upgrade, the Switch family could surpass Nintendo DS' lifetime sales (the Switch is currently at 62 million units sold, whereas the DS hit 154.02 million sold across its various iterations, so that's a tall order).
Bloomberg also reports that there are "major games" planned around its release, but that's probably one of the most vague Nintendo insider statements I've seen in a while. If Nintendo is planning an enhanced version of the Switch, you can bet they would want to promote it. It's just common sense.