You need to have a conversation with the manager of the Research department soon. Tell this person your position and let them know what you need to deliver for the company. "To do it right, I need to know the features and benefits of our product. We're just getting a handle on the product because R&D keeps saying 'in two months… in two months…' but that doesn't meet sales quotas, doesn't put food on the table."
Make it clear that their enthusiasm, innovation and creativity is great. But you need their help now. Be prepared. Create a script and get ready so you don't skip what's important to say assertively. There's a good four-step script for you to try - it uses a handy mnemonic device: REAP, as in "you reap what you sow."
R - Report what's happening - We need to make sales and we can't because we don't have a finished product.
E - Express your reaction - I feel frustrated because we can't sell what might be; we need to sell what exists now.
A - Ask what others can contribute - We don't want to stifle your enthusiasm but we want to make sales. What can we do that works now? What suggestions can you give me that will help us accomplish our common goal?
P - Payoff - the benefits to the other person. There's a payoff to me and my team and to you and your team. When we bring in enough revenue, it will fund R&D. We'll also bring back information from customers in the field that could help you and your effors to improve and innovate the products.
This isn't just an interdepartmental rivalry, it's a telling moment in your company's growth. If you come at it from a position where you value their strengths while asserting your own needs, everyone wins.