With Fab unlikely to still be playing after the end of the year it looks like just Ljubicic and Federer with the chance to play in every GS of this decade. Obviously they have had very different results.
Getting on the list & staying on it takes a combination of good health, keeping your ranking in the top 100, and some good luck. Ferreira surpassed Edberg to set the record & they obviously had much different results in majors. Hrbaty was the best chance among active players to pass Ferreira, but one injury did him in. Of the top five players on the "most consecutive weeks in the top 100" only one (Santoro) is on this list. The others (Moya, Grosjean, Hewitt, Ferrero) had injuries along the way that resulted in some absences.