Starcraft was not a clone of RTS games at the time... unless someone can come up with a game that competes with SC on things like polish, continuity, replayability, muiltiplayer fun, story, economics design, and overall balance (between 4 factions, not just 2, keep that in mind)... I think SC stands out umung the crowd. Starcraft, for all intents and purposes, was the measuring stick for RTS games for many years after it came out. From March 1998 when SC was released, the only decent competitor that came out that had the popularity of starcraft would be Westwood's C&C RA2, which came along in october 2000.
Blizzard makes great games... from the warcraft series (which were all anywhere from good to epic), Starcraft (lol @ those holding their breath for Starcraft Ghost to come out), and the Diablo series. Anyone ever heard of Rock and Roll Racing? That was made by Blizz too... no wonder it remains as one of my favorite games.
They take a long time to make a game, but damned if they aren't truely epic games. After playing plenty of games that had crazy graphics engines, but were cobbled together at the last minute and sent out the door (Supreme Commander, Hellgate London, for example), one has to appreciate the effort in design and thought that blizzard gives their games.
I won't get started about WoW... but damned if it's not the cheapest hobby to have.
I've only ever pre-ordered one game, but Diablo3 will be the second.