I've been holding back a bit on the publicity during pre-release stages of SGDK2 because it would probably be a big mistake to go hype something that doesn't work right and turn people off because then they think SGDK2 is a program that doesn't work (and won't try it again when it does). But I think it's ready now.
I suspect that publicity isn't the only difference between Game Maker and SGDK2, though (it'd be cool if it were). It's like the PS3 versus the Wii. The PS3 is technically superior, but the Wii appeals to a wider audience. Although SGDK2 may be technically superior in some regards, I think Game Maker might know better how to appeal to a "lower common denominator" by being more visual and covering a broader range of game types. (It seems that the author is now working for a company that is supporting the product full time now, so it could be hard to compete with that, except for the fact that SGDK2 is totally free and open with no registration or restrictions involved.)
What SGDK2 really needs is some big flashy games that demonstrate the power that it has that no other program has... what you can do with SGDK2 that you can't do nearly as easily with anything else. People who are looking around for a game creator don't have time to do a full investigation, but I think if they saw the games that a particular engine could create, they could be heavily swayed. I believe they call this the "
Killer App". SGDK2 could really use a Killer App. And I think SGDK2's killer app would be a huge epic platform game (that also includes some mini games and other non-side-scrolling views for parts) that's really fun to play ... so fun that people are dying to add their own levels to it or edit the existing levels. Maybe it would include a feature that seamlessly links to levels that are downloaded at runtime so the game is always changing or different every time you play.
But until this killer app exists, we'll just have to try recruiting people with old fashioned publicity. I'll begin that publicity myself when I do the official release, but you're welcome to get started early.