I remember that blowing our minds when we first saw it.
I miss all the Easter eggs in software. These days people just add the Konami code JS to their web site or app then pat themselves on the back for being original.
In the pre-win95 era, I think more MS programs had easter eggs than lacked them. Both solitare and minesweeper had cheat-codes (I used the latter to defeat my sister's high-score of 14s on small, getting a 2s. She was ufrious, erased all the high-scores and spent days getting her score back down to that).
Gates stepped down from his day-to-day responsibilities at MS in June of 2008. The entire Flight Simulator team was laid off in January of 2009.