I have used the Air France bus to get from the airport to the Concorde with good success. Is there a similar way to get from the airport to this new Hyatt Regency Etoile hotel?

It is the same hotel, different name.

Are you certain? I just stayed at the Concorde LaFayette and it hadn't changed names. Maybe you're thinking of a different Concorde.

Yes, He's certain. I'm currently in the Hyatt (Old Concorde Lafayette) as I type this. The name has now officially been changed.

Tell me more of this bus you speak of.

"GIYF dude"????

I had to google that one.

I see what you did there...

What do you want to know? Deviating into CDG? Spent all your DEV bank on a limo to work? Second cheapest option for getting from term 1 and 2 at CDG to (most) of our downtown hotels. (the cheapest BTW, is an RER ticket which can be purchased for 9.5 euro).
For the bus, the hardest part is finding the right location around the terminal. Make sure you get the LES CARS/AirFrance bus #2 and get off at the Porte Maillot stop. Hotel is next to the stop. I think the fare is 16 euros but I could be off a couple. Pay the driver with CASH.
Bus #1 goes to the Gare de Montparnasse, which is by our Montparnasse hotel, I believe across the street. Bus # 4 goes to the Gare de Lyon, which is not next to the Bercy hotel but a nice walk (20 mins) or two subway stops away. Enjoy!

How much time do you have ? My preference is taking the RER B then transferring to the C. It's a bit cheaper, and easier to find than the Air France bus. You get to see some nice scenery you don't see on the bus as well.