its like i was saying to my mate the other day about how i view games as intellectual success and failure, based on the evolution of a concept. i think even though supreme commander is a definate successor from total annihilation, it added enough new concepts and ideas to stand the test of time, i think in todays world that is rare in games. look at duke nukem as an example, its been about seven hundred years in development, is it bringing anything new or revolutionary to the table? no. so its gotta (at least for me) be considered a failure.
starcraft II failed in the same way, it was just too much of a 'remake' of the original, and didn't really change anything or add anything new (campaign was much much better than original), it still for me has the same bland rush based multi-player games that the first one had, supreme commanders sheer scale sometimes makes rushing pointless to even attempt and players benefit from actual tactics and strategy rather than quick, hard-hitting brute force. in supreme commander you can kill your opponant without ever setting foot into their 'base', it has proper electronic warfare and recon with spy planes, etc. so yeah, its the daddy of all RTS and nothing else is really worth considering, unless you've already played supreme commander.