Yes, but they all got demoted. I have the core gods all as demi gods in my game with a homebrew set of greater gods. Yondalla has been the most featured of the demi gods with Grumsch and Nurell being used a bit as well.
I use the core gods only if I'm running a game in a homebrew world that I developed for only a single campaign, and for which I haven't written much background info.
Any time I create a homebrew world for multiple-campaign use, or for a single but long-running campaign, a new pantheon is one of my first priorities.
Interesting choice for your representative sample...
I started a campaign this year with some new players, some old players new to D&D and some in between. To keep it simple, I used the Core Pantheon so that anyone with a Player's Handbook could make a Cleric, understand the clerics they meet, etc.
Pelor and Farlangn (sp?) are prominent because the Paladin worships Pelor and the Cleric chose Farlangn.
From the other side of the spectrum the bad guys 'worship' various powerful outsiders instead of dieties.
I hope your research is successful.
Game ON!
Nyrfherdr
In my homebrew, I use my own gods. For beginners, it's easier not to drown them in too much information, so a first time cleric usually starts with Pelor, because that's useful for the party.
Edit: I don't use Pelor with any kind of "personality" though. He's just in the starting kit for the cleric in the PHB . Gods in my campaign differ very much from core gods, and there's nothing like a fixed pantheon; the last point explains why Pelor does not disturb the assumptions of my campaign .
In our current Greyhawk campaign, St. Cuthbert, Hextor, Iuz, Nerull and Vecna have figured prominently. Zuggtmoy and Graz'zt have also (unfortunately) had a hand in some events.