the seal of quality was a useless thing all the games still go through the same testing routine as the SNES apart from now you actually get really detailed reports from them so the "quality" of games has actually improved since the SNES days.
regarding shovelware most of it doesn't even make it to the shop shelves so there no problem. But the problem is the great lack of good titles, which means all you see when you walk into your local game shop is a few good Wii games and about a dozen really bad ones.
and in regards to the limit that developers can produce... that's just plain wrong a single developer can put out a dozen good titles a year if they had the man power. Also I think you pointing the finger at the wrong person if you want to fix the shovelware problem, because its the publishers fault more than the developer they ask for X amount of games this year and developer x has to make them.
the world is backwards :s