I knew some would jump forth to defend Glorantha, and past products. I got into RQ with second edition in the early 80's but moved onto RQ3 the second it came out. Over the years I have played in a very large number of different systems, so I can't say RQ just rules and everything else can jump in a lake. I approach RQ from the point of view, that I want something specific. RQ is and always has been my favorite Sword and Sorcery style game. Deadly, brutal, with magic that is mysterious, but not overwhelming in power. Conan, Fafhrd and the Gray Mouser, The Book of Swords, all had incarnations in campaigns I ran over the years, it naturally lends itself to that. It is for this reason I have always liked RQ, but I don't care where it came from or what reasons the original creators had for making it.
The d100 system has survived because of its catering to niche markets. No matter how good the product, it has a limit as far as market appeal. Call of Chthulhu, Stormbringer, Hawkmoon, Fafhrd and the Grey Mouser, and especially Glorantha are all niche markets in a niche market. Part of this is being solved by making it OGL and allowing others to develop material for it. It may actually increase their market share, but the sad thing for me is that Glorantha continues to be the flagship of the RQ line. It has had its chance, and though there are many out there who love it the amount of new blood attracted by it is most likely going to continue to be at the anemic levels it has maintained over the years. Not a great way to insure profit, not just survival.
Though I am sure a significant portion of MRQ sales has been because of RQ die hards, the portion they need to be concerned with is everyone else because that is where growth is. I am not suggesting that the die hards don't count, you do. What I do suggest is that the die hards have been there from the beginning and the publishers of RQ have had medium success. They could pay the bills, pay themselves, get things printed, but I assure you none of them are rolling in dough because of it. I want to see the system continue to survive, and OGL is a step in the right direction.
Major support for a non Glorantha fantasy setting would go a long way to converting some of the d20 crowd, and finding new players in greater quantities. Continuing down the Glorantha road is like a comfortable exercise in futility. You have done it before, you know where it is going, but you continue to go there because it has proven to be moderately successful.
P.S. Vikings just proves my point, excellent product with a more generic plug and play where you like style. It was not Glorantha specific.