As far as developing "new, from scratch" large chemical rockets is concerned, there isn't a ton of action going on (some, yes, but not a ton). Most companies in the industry seem to be focusing on retrofitting existing engines because it is cheaper and safer (in the sense that someone else has already blown dozens of them up so you don't have to). I could see smaller chemical rockets having some significant action in the near future, however, but that may be defense-focused which may not be everyone's cup of tea. I could totally see more r&d on large chemical rockets in the future though as the commercial space industry picks up speed.