Actually, this forum is a very good place to "monitor" new products on the Ukulele market. Usually, some member sees something or hears something and shares it here. I remember such threads about Romero Creations, Blackbird, Kort, to name just a few that come to mind.
Also, most manufacturers of musical instruments present their new products at a merchants' show called NAMM. The show is each year in January in Annaheim, California. Almost all new products will first be introduced there. Again, a good place to check those out is this very forum. I usually start a thread to collect all the Ukulele related news, and many people who get to visit the show contribute their intel to that thread.